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SC05 · SCIENCE THROUGH EVIDENCE

College Physics I — algebra-based measurement and mechanics

Fifty-nine original destinations implement motion, force/contact, energy/momentum, rotation/statics, elastic, fluid, thermal, oscillator and wave evidence in this distinct algebra-based college course. The finite six-module scope and final synthesis/project pair are authored; independent learner and practical evidence remain separate gates.

This is the course outline. Open a unit to choose a lesson; every lesson opens on its own page. Explanations and experiments live inside those lesson pages.

Preparation and course boundaries

Preparation: Algebraic equations and ratios, scientific notation, square roots, basic right-triangle trigonometry and graph reading. Calculus is not required. Every investigation distinguishes synthetic data from actual measurements and explains its reference convention.

Course outcome: Across the authored categories, reconstruct motion from bounded records, audit position/time calibration, resolve vector components and relative frames, test projectile assumptions using changed-case residuals, and distinguish admissible force/contact branches from failed constraints and calibration artifacts, then close staged work-energy and impulse-momentum accounts with explicit systems and measurement alternatives, including angular readouts, supported rotational constraints and elastic-domain limits, fluid pressure references, buoyant/capillary constraints and transport-regime audits, phase/second-law constraints and coupled oscillator-thermal inference.

All lessons are directly accessible. Reused foundation explanations are identified where relevant; completing a different course does not award this course's evidence. The 59 registered lessons keep separate predictions, captures, practice responses and reflections.

Measurement, vectors and motion9 lessons

Use algebra to separate displacement from distance, measured records from hidden motion, frame changes from physical changes, and model mismatch from calibration error.

Calibrate position before interpreting a speed estimate

Compare scales 0.8,1.0,1.2 at offset 0.1 m, then change only offset. Retain anchor readings, raw and corrected speed and the stated raw interval. Propose an independent check for a nonlinear response that two anchors cannot exclude.

Find what a straight sampled track does not reveal

Compare amplitudes 0,0.25,0.5 m at one sampling interval. Retain the identical recorded points and different generator distances. State which extra observation time would distinguish constant motion from the selected hidden oscillation without treating the revealed curve as measured data.

Infer acceleration while auditing the clock

Compare a=1 at clock scales 0.8,1.0,1.2. Reconstruct one second difference and compare interval velocity with the fitted initial velocity. Then use a=0 to explain why a time-scale error cannot create curvature in this model.

Split a motion interval at its actual reversal

Compare v0=3,4,5 m/s at b=1, then compare b=1 and 2 at v0=3. Retain the event time, interval classification and separately calculated distance/displacement. Explain why extrapolating after 4 s requires another model claim.

Locate one meeting event in two inertial frames

Compare B velocities 1,3,5 at observer velocities 0 and2. Retain one actual event and two missing-future classifications. Reconstruct the transformed meeting coordinate without altering the event time.

Test whether a requested straight crossing is feasible

Compare current 0,1,2 at relative speed 2, retaining north-aimed drift and straight-across feasibility separately. Predict the equality boundary before checking. Explain which goal remains possible when current exceeds relative speed.

Find the landing event from the actual initial height

Compare vx=4 and12 at the same vy, then vy=−2, 0, 4 at vx=8. Retain the accepted root, endpoint and future maximum-height classification. State an observation that would challenge the no-horizontal-force assumption.

Distinguish an origin error from a failed projectile model

Compare a=0 and1 at offset 0.1 m, then change offset to −0.2 m. Retain raw, corrected and residual coordinates. Predict the second difference before checking and propose a separate timing/perspective test that the packet cannot supply.

Force evidence, contact and circular motion10 lessons

Construct recipient-specific force inventories, solve algebraic contact branches, and test inferred dynamics against independently supplied measurements.

Change force branches at a stopping event

Compare F=0,4,6,10 N at v0=2 m/s. Predict whether a stop exists and whether it lies in the 2 s interval. Retain the position and velocity at the event before evaluating the final state.

Separate apparent weight, mass and support contact

Compare support accelerations+2,−4,−10,−12 m/s² at one mass. Retain the conditional required normal and actual normal, then explain why the object cannot share the last prescribed acceleration.

Reject a circular path that needs a pulling surface

Compare speeds 4,6,8 m/s at R=4 m. Draw the two actual interaction forces, then calculate the inward resultant. Keep failed required normal separate from actual force and state what is not predicted after separation.

Use center distance in gravity and orbital comparisons

Compare radii R,2R,3R at one test mass; retain field, force, speed and period ratios. Then change mass alone. Explain why equal periods need not imply equal instantaneous speeds at every point of a noncircular orbit.

Infer inertial mass while retaining a force-reading fault

Compare offsets−2,0,2 N at zero fault, then vary fault at one offset. Retain slope, intercept and held-out residual. Propose a changed acceleration that would test a curved force law rather than merely repeat one fitting point.

Work, energy and momentum evidence10 lessons

Select the system, interval and reference frame before applying work-energy or impulse-momentum; retain inaccessible states, conversion channels and calibration alternatives.

Add work across changes of force and direction

Compare a positive first segment with a resisting second, then reverse both force signs. Keep separate applied contributions, total work and intermediate kinetic energy. Explain how a perpendicular guide force can matter to momentum without adding energy.

Test an energy target before taking a square root

Compare compressions0.5,0.8,1.0 m at a fixed target, then vary target at fixed compression. Retain the first inaccessible case and demonstrate algebraically that a common potential-energy offset cancels.

Close a thermal ledger at the actual stopping point

Compare requested distances1,2,4 m at friction 6 N, then double or halve friction where controls permit. Record requested versus actual distance and show both the point-only and object-plus-surface accounts without double-counting.

Distinguish a rate from an amount of energy

At T=2 s compare efficiencies0.4,0.8,1.0. Then keep one efficiency and change duration. Preserve energy and power units and explain why the two comparisons answer different questions.

Keep calibration ambiguity in an energy fit

Compare an η=0.8,s=1.1 packet with η=1,s=1 where available, then choose a state with apparent fraction above unity. Retain the product relationship and propose an independent measurement capable of separating its factors.

Separate pulse area from a force-reading baseline

Compare two durations at zero baseline, then introduce one nonzero baseline. Retain true and indicated areas separately and propose a pre-/post-pulse baseline check without pretending those observations were already supplied.

Preserve two momentum components through a point collision

Compare an oblique packet, a head-on partial cancellation and exact zero momentum. Retain both components and kinetic-energy accounts. Explain why the displayed chain is a vector addition diagram rather than the collision trajectory.

Track an internal energy release in two frames

Hold relative speed fixed and change U. Compare ground and center-frame velocities, momenta and kinetic energies. Then double u and predict the energy-source requirement before checking.

Angular records, statics, rotation and elastic limits9 lessons

Audit angular representations, moment arms, contact equilibrium and inertia inference; reconcile rolling/coupling accounts and apply elastic relations only within their declared domains.

Read an angular encoder without losing a revolution or reversal

Compare a steady wrap, an interior reversal and a zero-velocity endpoint. Preserve raw wrapped samples, disclosed unwrapped coordinates, signed displacement and swept angle. Explain which conclusions rely on the known generator rather than the samples alone.

Infer a load location while testing the support model

Compare a centered load, both zero-reaction boundaries and an outside state. At one feasible state vary the sensor offset and retain inferred position plus force residual. Propose an independent geometry or weight check rather than treating a fitted coordinate as a measurement of truth.

Fluid pressure, constraints and transport evidence8 lessons

Separate pressure references and calibration from density, test hydrostatic and buoyant constraints, and close flow mass/energy budgets only within declared capillary or viscous regimes.

Track gauge pressure across a density interface

Predict the interface and bottom pressures for two layer combinations with equal total depth. Preserve the continuous piecewise graph, gauge and absolute references, and explain why exchanging layer thickness changes the result.

Thermal systems, oscillators and introductory waves11 lessons

Audit state and path quantities, phase and second-law limits, infer oscillator/wave parameters under calibration alternatives, and connect lost mechanical energy with a finite thermal receiver.

Infer an interface temperature from a steady heat ledger

Compare equal and unequal thermal resistances, then alter only one layer. Retain both temperature drops and equal steady rates; identify a separate radiation or convection term that would invalidate a conduction-only inference.

Cumulative algebra-based evidence and project2 lessons

Combine motion, force, rotational, fluid and thermal accounts while preserving system boundaries, calibration alternatives and independently assessed transfer.

Reconcile falling-mass rotation with a separate stopping receiver

Predict the acceleration and tension from separate recipient diagrams before checking energy. Compare two heights and two capture fractions, preserve the two time intervals, and retain a rejected 10 N cord-capacity alternative. Explain what an independent timing or temperature calibration could challenge.

Audit a whole flow-power account before inferring efficiency

Retain input, fluid, height, kinetic, pipe and pump powers for contrasting settings. Infer efficiency from an independent hypothetical wattmeter record, then propose a new observation distinguishing an input-power bias from a thermal-capture error. Preserve original prediction, critique and revision in the course project.

Investigation portfolio

Keep predictions before comparison, complete raw records and units, explain competing models and test a changed case. Supplied and simulated data are labeled in each lesson. A saved notebook is not proof of experimental technique or correct reasoning.

Force inventories and system boundaries

Evidence to retain: Retain separate recipient diagrams, a component residual, pair-system balance and a held-out force-reading test. Distinguish an inferred missing interaction from an independently identified agent.

Boundary: Original synthetic forces and acceleration labels; no apparatus calibration, physical cart collisions or demonstrated practical competence.

Unilateral and friction-state feasibility

Evidence to retain: Preserve conditional required force and admissible actual force, an exact or continuous boundary, a stop/lift-off event and the new branch. Compare maximum static capacity with actual friction.

Boundary: Virtual point/contact models only, not lifting, braking, lift operations or physical ramp instructions.

Force balance and curved-motion comparisons

Evidence to retain: Compare a force-versus-speed equilibrium with a trajectory constraint, retain a rejected circular-contact state and derive a common-source orbital scaling without confusing radius and altitude.

Boundary: Assigned drag, spherical-source and point-contact assumptions; no real falling, driving, ride safety or orbital flight prediction.

Signed work and accessible energy paths

Evidence to retain: Retain separate work contributions, an intermediate kinetic-energy check, a turning or stopping boundary and two different system-boundary accounts without counting thermal conversion twice.

Boundary: Virtual points, ideal guides and assigned friction; no real compressed springs, launches or stopping-distance safety certification.

Energy-rate and impulse measurement audit

Evidence to retain: Compare input/output energy and average/endpoint power, expose the loss-times-speed-scale product, and preserve true versus baseline-biased impulse over a declared recording window.

Boundary: Synthetic readouts and disclosed generator settings; no actual power measurement, force-sensor calibration or practical instrumentation claim.

Collisions, release and consecutive-stage boundaries

Evidence to retain: Solve momentum components and one supplied response rule, account for kinetic conversion or internal release, compare frames and choose separate conservation statements for collision and rise.

Boundary: Point collisions without retained rotation, negligible stated external impulse and ideal later guide; no physical impact, ballistic apparatus or explosive procedure.

Angular representation and rigid-point geometry

Evidence to retain: Retain wrapped/unwrapped records, a reversal split, radian conversions, velocity/acceleration components and two equivalent moment-arm calculations. Distinguish a coordinate jump from a physical event.

Boundary: Disclosed fixed-axis generators, not unambiguously reconstructed sparse encoder data or real machinery.

Static and dynamic rotational inverse evidence

Evidence to retain: Check unilateral support feasibility before inverting a reading; preserve force-closure residual, mass-distribution/axis contributions and a held-out torque-reading challenge.

Boundary: Synthetic sensors, provided uniform-bar inertia and ideal contacts; no measured load capacity or bearing certification.

Elastic geometry and extrapolation audit

Evidence to retain: Convert area units, retain stress/strain/extension and a rejected extrapolation; distinguish specimen stiffness from material modulus and compare supplied shear/bulk ratios.

Boundary: Hypothetical linear coefficients and imposed strain limit, not yield, fracture, safe working load or material testing.

Static fluid references and calibration

Evidence to retain: Retain a two-volume density inference and unused volume check, continuous layered pressure graph, gauge/absolute conversion and paired hydraulic work accounts.

Boundary: Synthetic additive balance error and ideal static/quasistatic fluids; no physical pressure rig or instrument calibration claim.

Mass, mechanical energy and viscous-regime audit

Evidence to retain: Close branch volume/mass balances, distinguish imposed split from predicted split, reconcile pressure-work power with height/kinetic/loss terms, and reject a radius extrapolation that fails its laminar screen.

Boundary: Steady mathematical flow packets and approximate Reynolds guide; no pump, plumbing, exposure or clinical advice.

Thermal state and phase-boundary audit

Evidence to retain: Retain affine temperature anchors and an unused check, absolute gas-state ratios and a partial/exact/complete melting comparison including receiver capacity.

Boundary: Disclosed ideal gases and simplified calorimetric constants; no physical heating, pressurization or measured material claims.

Thermal transport and process admissibility

Evidence to retain: Close series conduction drops, compare endpoint energy with route heat/work, and retain an energy-balanced proposal rejected by reservoir entropy.

Boundary: Specified transport and equilibrium assumptions, not actual thermal machinery, emissions or safety certification.

Oscillator calibration and response discrimination

Evidence to retain: Compare shared-clock and independent-static parameter evidence, retain a held-out pendulum record, and separate free decay from finite driven response.

Boundary: Small-amplitude ideal models; supplied finite-amplitude and viscous-response expressions are optional algebraic enrichment, not physical loading.

Coupled mechanical-to-thermal ledger

Evidence to retain: Derive acceleration and tension from separate recipient diagrams, reconcile translation/rotation/axle energies and distinguish descent from terminal stopping. Retain a failed cord constraint and independent timing/temperature check.

Boundary: Fictional bounded mechanism; no physical rig, load, brake, heating or safe operating limit.

Flow-power inference dossier

Evidence to retain: Close input/fluid/exported/loss powers, connect receiver warming to a stated capture boundary and compare actual rival wattmeter/flow/thermal calibration hypotheses.

Boundary: Specified virtual flow and receiver, not electrical installation, plumbing, clinical measurement or practical efficiency certification.

Calibration and undersampling audit

Evidence to retain: Freeze competing offset, scale, clock and hidden-motion explanations; retain contrasting recipes, raw records, corrected differences and one independently justified new observation.

Boundary: Synthetic affine sensors and disclosed smooth tracks, not observed apparatus. Exact reference anchors and time assumptions must not become unstated empirical claims.

Event and model-discrimination portfolio

Evidence to retain: Locate a reversal or ground event before evaluating endpoint claims, separate distance from displacement, then compare offset and curvature alternatives with changed numerical observations.

Boundary: No physical drops or launches; constant acceleration and known timing are hypotheses to examine, not guaranteed real-world behavior.

Mixed assessment and cumulative project

Open the retained response and project workspaces. Practice, saved work and independently reviewed proficiency remain separate.

Mixed assessment and retained reasoning

These 46 course-specific public tasks are practice, not a secure examination. Each retains up to three immutable written responses, known feedback exposure before each response, and human rubric critiques. Drafts remain editable. No text-length check or self-reported review certifies correctness, independence, laboratory skill or mastery.

1. A pair law and a missing force are different inferences

A 3 kg point has independently supplied acceleration (2,−1) m/s² but listed forces total (4,−3) N. Infer the missing component. Separately a 2 kg rear cart and 4 kg front cart touch on a frictionless line; 12 N pushes the rear. Find acceleration and contact. Then apply −12 N only to the rear with no tether: give both accelerations and the pair center-of-mass acceleration.

Course-specific review criteria

  • Sum signed components for one recipient and identify independent premises.
  • Cancel internal forces only for the combined system.
  • Reject negative compressive contact and retain distinct component accelerations.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

2. An angled pull and an accelerating support

A 2 kg point slides right while pulled with 10 N at 30° above horizontal; g=10 and μk=.2. Find N, friction and horizontal acceleration. Separately a 3 kg point begins at rest touching a support prescribed to accelerate downward12 m/s² for 1 s. Find actual normal, object acceleration and gap above support. Explain why neither calculation permits a negative actual normal.

Course-specific review criteria

  • Resolve a single applied force without double-counting its components.
  • Use the normal reaction, not weight by habit, in friction.
  • Release infeasible contact and compute relative separation from common initial conditions.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

3. Static demand and a stop-and-stick boundary

A 2 kg point is initially at rest on a slope with sinθ=.3, cosθ=√.91, g=10 and μs=.5: find required static friction and test capacity. Separately a 2 kg slider starts rightward at 3 m/s under 6 N kinetic friction leftward and 2 N drive rightward. Static capacity is 10 N. Find stop time and displacement after 2 s, explaining the post-stop force.

Course-specific review criteria

  • Compare static demand with its maximum instead of assuming equality.
  • Locate the first zero-slip event before evaluating the final state.
  • Use the new admissible static balance after stopping.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

4. Terminal balance is not a circular constraint

A falling1.8 kg point has quadratic resistance k=.2 kg/m and g=10. Find terminal speed and signed downward acceleration at twice that speed. Separately a 3 kg point at a convex crest R5 m moves at 5 m/s: find normal. What changes at 10 m/s? Give actual instantaneous acceleration after failed contact, not the rejected circular value.

Course-specific review criteria

  • Keep velocity direction distinct from acceleration sign.
  • Treat centripetal force as the net inward resultant, not another interaction.
  • Reject a tensile surface force and name the uncomputed post-separation trajectory.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

5. Altitude and common-source orbital scaling

An ideal spherical source has surface radius R. Compare exterior gravity at altitude R and altitude 3R. Compare circular speed and period at those locations for the same dominant source. Would doubling the negligible test mass change force, gravitational acceleration or circular speed? State where the center is in a general elliptical orbit.

Course-specific review criteria

  • Convert altitude to center radius before using inverse-square gravity.
  • Derive speed and period ratios with distinct exponents.
  • State test-mass/common-source assumptions and distinguish circular from general elliptical geometry.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

6. A mass slope with a bounded reading fault

At independently exact accelerations1 and 3 m/s², force readings are5 and 11 N. Infer mass and intercept. A held-out reading at 2 m/s² is 7.8 N: compute observed-minus-predicted residual. If each fitting force reading independently has a bounded±.1 N error, find the worst-case mass-error bound. Does this automatically cover acceleration-scale error or establish a unique cause of the residual?

Course-specific review criteria

  • Distinguish additive offset from slope and preserve the unused observation.
  • Propagate worst-case bounds with units and explicit exact quantities.
  • Avoid interpreting a deterministic bound as confidence or a residual as a unique mechanism.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

7. A signed work sum and an inaccessible spring target

A 3 kg point starts with K=6 J and receives works +12 and−4 J, with all other work zero. Find final K and speed. Separately a 1 kg point receives a fully relaxed spring’s energy with k=40 N/m and initial compression .5 m. Under g=10, can it reach .75 m above release level? Find the actual maximum height and K at .4 m. Explain what adding100 J to gravitational potential at both endpoints changes.

Course-specific review criteria

  • Sum signed contributions and distinguish total from selected work.
  • Check an endpoint against the accessible energy budget before taking a speed root.
  • Keep a reference shift separate from a changed physical energy term.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

8. One thermal conversion and two power measures

A point starts with15 J kinetic energy and constant resisting friction3 N, with no drive. Compare requested paths4 and6 m: give actual distance, remaining K and object-plus-surface thermal gain. Separately a device delivers30 J useful energy in3 s at efficiency .6: find input energy and average input power. Can endpoint power be found from just those three numbers?

Course-specific review criteria

  • End sliding at its first stop rather than at an inaccessible requested point.
  • State whether the surface is inside the energy boundary.
  • Distinguish energy, average power and unprovided instantaneous power.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

9. Squared speed bias and a force baseline

A height-to-speed generator has true kinetic fraction .75 and speed readout scale1.1. What apparent fraction is inferred? Can three exact height points separate these parameters? Separately a 2 kg point begins at−2 m/s and receives a triangular true net force pulse of peak12 N over1 s. A readout baseline+.2 N affects the full record. Find true and indicated impulses and true versus inferred final velocities.

Course-specific review criteria

  • Square the speed scale in energy inference.
  • Separate disclosed generator truth from what the observations identify.
  • Integrate the baseline over the stated full window and retain signed initial momentum.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

10. Momentum plus a supplied response

A 2 kg point at4 m/s hits a stationary3 kg point with negligible external impulse. Using the supplied optional recovery relation v2−v1=.5(4−0), find both final velocities and kinetic-energy conversion. Compare the same masses in a sticking collision and explain why momentum alone does not choose either response.

Course-specific review criteria

  • Use signed momentum and the explicitly supplied response equation.
  • Check separation and both kinetic-energy terms.
  • Do not pretend the empirical response follows from momentum conservation alone.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

11. Vector sticking and an internal release in another frame

A 2 kg point at(3,0) m/s sticks to a 1 kg point at(0,3) m/s without external impulse or retained rotation. Find common velocity, speed and kinetic conversion. Separately masses1 and3 kg initially share ground velocity2 m/s and release with final relative speed4 m/s and no external impulse: find final velocities and the kinetic increase. Compare that increase in the center-of-mass frame.

Course-specific review criteria

  • Conserve planar components before taking a magnitude.
  • State the point/no-rotation approximation for the sticking energy account.
  • Distinguish frame-dependent kinetic energy from this frame-invariant increase at unchanged total momentum.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

12. A short collision does not license a long-time momentum shortcut

A 1 kg point at6 m/s sticks to a stationary2 kg point in a short horizontal collision with negligible external horizontal impulse. The combined point then rises without mechanical loss on a guide under g=10. Find immediate common speed, collision kinetic conversion and maximum rise. Explain why neither initial kinetic energy nor total point momentum can be carried unchanged through both stages.

Course-specific review criteria

  • Use collision momentum to set the next stage’s initial condition.
  • Retain collision internal conversion rather than treating incoming K as later gravitational gain.
  • Name external interactions and explain why the long-time point momentum is not conserved.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

13. A reversal and the motion of an off-axis point

A fixed-axis body starts with omega2 rad/s and constant alpha−1 rad/s² for3 s. Find signed angular displacement, swept angle and final omega. At the final instant, a point is .5 m from the axis: find speed, inward acceleration magnitude, signed tangential acceleration and total acceleration magnitude. Could wrapped endpoint angles alone establish the swept angle?

Course-specific review criteria

  • Locate reversal before summing swept versus signed angle.
  • Use radians and distinguish angular rates from radius-dependent linear components.
  • State what the generator assumes beyond the sparse angular observations.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

14. A torque snapshot and a biased support reading

A10 N force acts at radius .4 m at30° above an outward horizontal lever. Find signed torque and explain why work is not yet determined. Separately use the taught12 N beam plus24 N load with supports x1 and3. True load coordinate2 m; right readout has+1 N bias and left readout is unbiased. Find actual reactions, indicated right force, inferred coordinate and force-closure residual. What if the actual load coordinate is0?

Course-specific review criteria

  • Use the signed perpendicular moment arm, not full radius by habit.
  • Keep actual force, indicated force and inferred location distinct.
  • Check force and torque balances plus unilateral contact admissibility.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

15. An axis shift and a drive-torque slope

The taught2 kg,2 m bar carries two1 kg points at±.5 m. Find central inertia and inertia about a parallel axis .5 m away, then net torque for alpha2 rad/s² about that axis. Separately drive torques3 and9 N m correspond to exact angular accelerations1 and4 rad/s² under constant opposing torque. Infer inertia and resistance; predict an independent reading at alpha2.

Course-specific review criteria

  • Include all masses in the parallel-axis term and name the axis.
  • Use net torque for I alpha and distinguish it from drive torque.
  • Retain an unused prediction rather than describing a two-point fit as calibration.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

16. A valid rolling prediction and its failed neighbor

An ideal rolling body has beta=1, mass2 kg, radius .5 m, available mu_s=.30 and g10. Compare slopes30° and40°. Calculate required coefficient and classify no-slip feasibility. For the feasible case, find speed squared and translation/rotation energies after a .6 m vertical drop. Explain why simply clipping friction at .30N in the failed branch does not preserve the no-slip acceleration.

Course-specific review criteria

  • Test static capacity before using a rolling constraint.
  • Close translational plus rotational energy with the correct supplied shape factor.
  • Reject a failed branch instead of modifying one force while leaving all conclusions unchanged.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

17. Signed angular impulses with internal energy conversion

Coaxial rotors I1=2,omega1=3 and I2=1,omega2=−2 lock with negligible external angular impulse. Find total L, common final rate, initial/final kinetic energy, internal conversion and the angular impulse on each rotor. Explain what changes if the pair receives an unmodeled external angular impulse.

Course-specific review criteria

  • Retain angular-velocity signs and a common axis.
  • Show component impulses cancel only for the combined system.
  • Reconcile kinetic conversion without pretending angular momentum conservation implies energy conservation.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

18. A specimen model is not a strength certificate

A hypothetical linear specimen has E=10^10 Pa,L1 m,A2 mm² and tension10 N, valid only through strain .001. Find stress,strain and extension in mm. Repeat with area1 and .5 mm²: identify supported and unsupported predictions. Separately supplied shear modulus4e9 Pa under shear stress2e6 Pa and bulk modulus2e9 Pa under pressure increase1e6 Pa: find the corresponding dimensionless shear strain and signed volume fraction change.

Course-specific review criteria

  • Square the length-unit conversion for area and keep strain dimensionless.
  • Respect the stated linear domain and distinguish extrapolated candidate from actual prediction.
  • Use the correct deformation modulus and do not infer yield or safe load from elastic ratios.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

19. A balance intercept and layered pressure reference

An unknown liquid gives mass indications 66 g at 80 cm³ and 146 g at 180 cm³ under a common additive balance offset and exact volumes. Infer density and offset; predict a held-out reading at 130 cm³. Separately oil density 800 kg/m³ occupies 0.3 m above 0.2 m water density 1000. With g=10 and atmospheric pressure 100000 Pa, find interface gauge, bottom gauge and bottom absolute pressure.

Course-specific review criteria

  • Convert mass/volume units and distinguish slope from intercept.
  • Retain the unused prediction rather than asserting two points prove calibration.
  • Add pressure contributions by depth and keep gauge/absolute references distinct.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

20. Force amplification with a displacement and work cost

Ideal equal-elevation pistons have areas 3 cm² and 15 cm². Input force is 12 N over 0.2 m. Find pressure increase, balanced output force, output displacement and both works. What changes in the argument if the pistons have different elevations or fluid leaks?

Course-specific review criteria

  • Use area in square metres and transmit pressure rather than equal force.
  • Close volume and work independently.
  • Identify which premise supports each equality.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

21. An impossible overhead tension and a separate floating state

A rigid 200 cm³ object has mass 120 g in liquid density 800 kg/m³, g=10. Find full-submersion buoyancy and required overhead-cord tension. Is the stipulated static state feasible? In a separate free-floating configuration find displaced volume and submerged fraction. Repeat feasibility at mass 200 g, with the same volume and liquid.

Course-specific review criteria

  • Distinguish displaced liquid volume from whole object volume by configuration.
  • Reject a negative required cord tension rather than report a feasible scale reading.
  • Check the floating volume against the object volume.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

22. Surface-force sign and distinct curved interfaces

Use supplied capillary law h=2γcosθ/(ρgr) with γ=0.05 N/m, ρ=1000, g=10, r=1 mm. Compare θ=0,90,120 degrees. What happens if radius halves? Separately use supplied drop and two-surface bubble laws 2γ/R and 4γ/R at γ=0.03 N/m,R=2 mm.

Course-specific review criteria

  • Retain contact-angle convention and signed cosine.
  • Convert millimetres before applying inverse-radius scaling.
  • Distinguish one interface from a two-surface film and keep force/length versus pressure units.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

23. A prescribed flow split and an independent power ledger

Steady incompressible flow of density 900 kg/m³ enters at 6 L/min and one outlet carries 3 L/min; second outlet area is 2 cm². Find its mean speed and mass flow. Separately use the taught water-flow packet Q=.002 m³/s, inlet/outlet speeds 1/2 m/s, inlet gauge pressure 30000 Pa, g=10, outlet elevation 2 m and prescribed loss 10000 Pa. Find outlet gauge/absolute pressure under atmosphere 100000 Pa and reconcile the pressure-work power decrease.

Course-specific review criteria

  • Distinguish volume flow, mass flow and section speed with correct conversions.
  • Preserve gauge and absolute references even for negative gauge pressure.
  • Close energy per volume and power without confusing separate packets.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

24. A radius extrapolation and molecular transport comparison

For the taught liquid and tube at radius 1 mm and pressure drop 1000 Pa, a report proposes Q=π×10⁻⁷/8 m³/s. Audit this proposed number independently using Q=πr⁴Δp/(8ηL), η=.001,L=1. Then find mean speed and Reynolds number with ρ=1000. Double radius at unchanged pressure and classify the new conditional regime. Separately with supplied xrms=√(2Dt), what happens to typical displacement when time quadruples?

Course-specific review criteria

  • Recompute powers of metres rather than trusting a printed candidate.
  • Apply radius scaling to flow, area, speed and Reynolds number separately.
  • Treat the new regime screen as a limitation and distinguish diffusion displacement from bulk flow.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

25. Temperature calibration before an absolute gas ratio

An affine thermometer reads 3 °C at true 0 °C and 87 °C at true 80 °C. A new sample reads 45 °C. Infer true Celsius and kelvin temperature. A separate fixed-volume ideal gas starts at 250 K and ends at 400 K; find its pressure ratio. Compare molecular rms speeds at the same temperature for two species with molar masses M and 4M. A 2 m rod with supplied alpha 1.5e−5/K warms by 20 K: find expansion.

Course-specific review criteria

  • Separate sensor gain/offset from true temperature and interval size.
  • Use absolute quantities and fixed n, V premises for the gas ratio.
  • Keep species mass scaling and geometry-dependent expansion distinct.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

26. Three final phases in one calorimeter model

Use the taught .5 kg liquid, 100 J/K cup, c 4000 J/(kg K), latent heat 300000 J/kg and .14 kg ice initially 0 °C. Compare initial warm-liquid/cup temperatures 10, 20, 30 °C. Find melted mass, remaining ice and final temperature in each; explain what omitting the cup changes.

Course-specific review criteria

  • Choose the phase branch before a final-temperature equation.
  • Retain equality as an exact boundary with zero residual ice.
  • Include each initially warm and finally warmed component consistently.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

27. A series interface and a separate radiative exchange

Two series layers have resistances .3 and .5 K/W between hot 330 K and cold 306 K, with no side loss or interface storage. Find heat rate and interface temperature when the .3 layer touches the hot boundary. Separately a supplied gray surface has epsilon.5, A 1 m², T 300 K, surroundings 290 K and sigma 5.67e−8 SI. Find net outward radiative power; what changes at equal temperatures?

Course-specific review criteria

  • Use equal steady heat rates rather than equal temperature drops.
  • Use kelvins and the net fourth-power difference for radiation.
  • Keep separate packets and omitted mechanisms explicit.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

28. Endpoint energy, route heat and an impossible cycle proposal

A monatomic ideal gas goes from 100 kPa, 1 L to 150 kPa, 2 L. Compare pressure-first then expansion with expansion-first then pressure increase. Compute DeltaU, W, Q for each. Separately a cyclic engine takes 600 J from 400 K and proposes 180 J work while rejecting the remainder to 300 K. Audit both laws. For a reversible refrigerator between the same temperatures with 20 J work, find removed and delivered heats.

Course-specific review criteria

  • Preserve work-by-gas and heat-into-gas signs and kPa L→J.
  • Distinguish state change from route and cycle quantities.
  • Test total entropy and name the performance ratio before interpreting it.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

29. A spring phase record with shared-clock ambiguity

An ideal spring oscillator has m 2 kg, k 18 N/m, A.2 m and starts at positive amplitude at rest. Find angular frequency, period, maximum speed, total energy and velocity after a true quarter period. If the clock reads 1.1 times true time, what stiffness is inferred from the uncorrected period? Separately a small-angle pendulum period-squared fit has slope 4pi²×1.1²/10 and an inferred length offset.05 m; does correcting the length offset alone recover g 10?

Course-specific review criteria

  • Relate phase, velocity sign and energy instead of reporting only a period.
  • Square the clock gain in period-based inference.
  • Identify shared calibration as a rival explanation across apparently distinct experiments.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

30. A free envelope is not a forced-response amplitude

Using the supplied optional models, take m 1 kg, k 4 N/m, drive amplitude.2 N and damping c.8 kg/s. Find the steady amplitude at Omega 2 rad/s and the free-envelope ratio after 4 s. Compute the displacement resonance frequency sqrt(k/m−c²/(2m²)). Why are the three results not one free-motion trajectory?

Course-specific review criteria

  • Use the supplied response relation with units and finite damping.
  • Distinguish envelope, instantaneous displacement and steady amplitude.
  • Name input/loss boundaries and avoid equating every resonance with the undamped natural frequency.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

31. Separate traveling interference, standing modes and beats

A nondispersive string has speed 6 m/s and frequency 3 Hz. Find wavelength and period. Two same-direction waves each have amplitude.01 m and phase difference 120 degrees: find resultant amplitude and intensity ratio to one wave at the same medium/frequency. Separately a 3 m fixed-end string has the same speed: which harmonic is 3 Hz? What beat frequency comes from 4 and 4.5 Hz?

Course-specific review criteria

  • Infer spatial and temporal quantities separately with correct units.
  • Add coherent signed disturbances before using amplitude-squared intensity.
  • Keep traveling, standing and unequal-frequency beat conditions distinct.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

32. Lost spring energy and a conditional capture inference

Use m 2 kg, k 200 N/m, A.2 m, receiver capacity 20 J/K and initial receiver temperature 300 K. At capture fraction.8 find energy partition, temperature rise and undamped period. A later packet at the same nominal amplitude gives rise.10 K: infer fraction conditionally, then name two rival causes other than a real capture change. What happens to rise and ideal period if amplitude doubles at fixed fraction/capacity?

Course-specific review criteria

  • Close whole-system and receiver-only accounts without equating them.
  • Treat an inferred fraction as conditional on calibration, capacity and initial state.
  • Distinguish amplitude-dependent energy from ideal amplitude-independent period.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

33. Motion records, vectors and a changed observer

A position sensor obeys xread=1.1x+0.2 m and reads 0.2, 1.3, 3.5 m at exact times 0, 1, 2 s. Recover actual positions and interval-average velocities; can these samples alone determine total distance if reversals may occur between frames? Separately two consecutive displacements are(3, 4) m and(−1, 2) m. Find resultant and magnitude. If two objects have velocities 3 and 1 m/s along the same axis, does changing to an observer moving at−2 m/s change their relative velocity?

Course-specific review criteria

  • Correct scale and offset before interpreting differences.
  • Distinguish sampled displacement, interval velocity and unobserved path distance.
  • Use signed vector components and preserve relative-velocity invariance.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

34. A friction switch and a recipient-boundary check

A hypothetical 2 kg block on a level surface has g 10, mu_s.4, mu_k.3. Compare rightward applied forces 5 and 10 N from rest: classify motion and find friction/acceleration. Once moving right, the drive is removed: find deceleration and stopping distance from 2 m/s under the same kinetic model. Why cannot the block–surface reciprocal friction pair be canceled in the block-only force diagram?

Course-specific review criteria

  • Use a static inequality before selecting the kinetic branch.
  • Split motion at the stopping event rather than extending a fixed friction direction.
  • Keep recipient and combined-system force diagrams distinct.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

35. Work, sticking and a later spring endpoint

A 2 kg cart starts at rest and receives constant net force 6 N over 3 m on a horizontal track. It then sticks to a stationary 1 kg cart with negligible external impulse. Find incoming speed, common speed and kinetic energy converted during sticking. The combined cart then compresses an ideal spring k 12 N/m on a frictionless track. Find maximum compression. State which conservation law applies in each interval and whether the pair’s kinetic energy was conserved in the collision.

Course-specific review criteria

  • Name the time interval and selected system before each equation.
  • Retain signed momentum and distinguish it from kinetic conservation.
  • Carry the post-collision rather than pre-collision energy into the spring stage.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

36. Support inference, angular momentum and a material boundary

Use the taught beam weight 12 N atx 2, load 24 N atx 2 and supportsx 1/x 3. Right sensor reads 19 N, left 18 N. Infer load coordinate if the right sensor is wrongly assumed exact and calculate force residual. Separately rotors I 1=2, omega 1=3 and I 2=1, omega 2=−2 lock without external angular impulse: find final omega and energy conversion. A specimen E 1e 10 Pa, L 1 m, A.5 mm² under 10 N is stipulated linear only through strain.001: is the linear extension prediction admissible?

Course-specific review criteria

  • Separate actual/readout/inferred quantities and test both balances.
  • Use signed angular momentum with a separate energy account.
  • Reject the material extrapolation without inventing a strength or failure result.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

37. Pressure, buoyancy and a failed radius extrapolation

Oil density 800 occupies.2 m above.3 m water density 1000, with g 10 and atmosphere 100000 Pa. Find bottom gauge/absolute pressure. A 200 cm³ object of mass 150 g is separately fully submerged in water with only an overhead cord: find required tension and classify feasibility. For another straight tube whose conditional laminar Reynolds number is 250 at radiusr, double radius at fixed pressure drop, viscosity, density and length. Find the new conditional Reynolds number and explain the resulting limitation.

Course-specific review criteria

  • Add layered pressure with an explicit reference.
  • Check the sign capability of the actual constraint before reporting a reading.
  • Track separate geometric scalings and recheck the model regime.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

38. A phase threshold and an independent cycle audit

Use the taught .5 kg warm liquid plus 100 J/K cup at 20 °C, .14 kg ice at 0 °C, c 4000 and latent 300000. Find the final phase/temperature. Separately an adiabatic gas does 80 J work: find DeltaU under work-by-gas convention. A cyclic engine absorbs 800 J from 400 K and proposes 320 J work, rejecting the remainder to 300 K. Audit energy and total reservoir entropy; does correct energy arithmetic establish admissibility?

Course-specific review criteria

  • Check the phase equality before solving a liquid-only equation.
  • Use explicit heat/work signs and distinguish the separate packets.
  • Apply total entropy to a cyclic working substance plus reservoirs.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

39. A shared clock, a wave snapshot and coherent intensity

An ideal spring m 2 kg, k 8 N/m, A.1 m is recorded by a clock reading 1.1 times true time. Find true/indicated periods, uncorrected inferred stiffness and true maximum speed. Separately a nondispersive wave speed 6 m/s at 3 Hz combines with an equal same-direction wave of phase difference 120 degrees. Find wavelength, resultant amplitude for individual amplitude.01 m, and intensity ratio to one wave at that same frequency. Why is this not a standing-wave construction?

Course-specific review criteria

  • Square clock gain in dynamic inference and retain true versus indicated quantities.
  • Use v=f lambda and coherent displacement addition before intensity.
  • State propagation and boundary conditions rather than naming a pattern from amplitude alone.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

40. Two complete energy accounts and one calibration alternative

For the taught drum packet take h 2 m and terminal receiver capture .5, with an idealized negligible-displacement terminal stop (no additional gravitational work). Find acceleration, tension, speed, translational/rotational/axle energies and receiver rise. For the taught pump packet take Q.2 L/s and eta.6. Find input power, pipe/pump heat powers and receiver rise after 60 s. If the pump receiver instead warms 2.0 K with all other readings unchanged, name two alternative explanations rather than declaring efficiency uniquely known.

Course-specific review criteria

  • Reconcile force/torque and energy rather than relying on one equation.
  • Keep descent, stopping, pump and pipe intervals/recipients distinct.
  • Preserve competing measurement explanations and propose a discriminating independent observation.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

41. A position correction is not a clock calibration

True position anchors 0 and3 m read 0.2 and3.8 m. A target indicated displacement 2.4 m takes a displayed 2 s. Infer the position-corrected average velocity if clock readings are exact. Then suppose displayed elapsed time is 1.25 times true elapsed time: revise velocity. Explain why the two position anchors cannot resolve the clock scale.

Course-specific review criteria

  • Solve scale and offset from common reference units.
  • Separate corrected distance from displayed versus true elapsed time.
  • Identify an independent observation rather than treating two spatial anchors as a clock test.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

42. Equal sample slopes and a reversal boundary

A record gives positions 0,2,4 m at times 0,1,2 s. What average velocity is established, and why is traveled distance not uniquely established? Separately x=4t−t² m over 0–3 s: find final displacement and traveled distance, retaining the reversal time.

Course-specific review criteria

  • Distinguish sampled evidence from an interpolated trajectory.
  • Locate the interior event and split path distance correctly.
  • Keep interval-average velocity distinct from instantaneous motion.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

43. A route and a meeting use different vector questions

A route goes 6 m east then 8 m north: find displacement magnitude, direction from east and distance. Separately A starts 0 at 4 m/s and B starts 5 m ahead at 1.5 m/s. Find meeting time and ground coordinate; transform the event to an observer moving −2 m/s whose origin matches at t=0.

Course-specific review criteria

  • Add components rather than route lengths for resultant displacement.
  • Use relative closing velocity and reject inappropriate speed addition.
  • Transform the event coordinate without changing its elapsed time.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

44. Equal speed is an exact feasibility boundary

A virtual channel is 12 m wide with current 3 m/s eastward. Relative-water speed is 5 m/s. Compare north-aimed relative motion with a directly opposite ground path: give times, drift for the first and heading for the second. Explain what changes if relative speed becomes 3 m/s. This is only a vector model, not practical route advice.

Course-specific review criteria

  • Specify whether each velocity is relative to water or ground.
  • Use the remaining perpendicular component rather than a scalar speed difference.
  • Retain the exact equality boundary and distinguish opposite-bank from opposite-point goals.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

45. An elevated launch and a misleading apex

An ideal virtual projectile starts 5 m above ground with horizontal velocity 6 m/s and vertical velocity 0, under g=10. Find ground time, range and impact velocity components. Compare horizontal velocity 12 m/s. Would vertical velocity zero at the start imply zero vertical acceleration? State one assumption needing independent evidence.

Course-specific review criteria

  • Solve the actual initial-height event and choose the future root.
  • Share elapsed time between independent components.
  • Distinguish velocity from acceleration and state a testable model assumption.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

46. Curvature, origin and an unknown cause

At exact times 0,0.2,0.4 s, indicated horizontal positions are0.1,0.88,1.62 m. Infer signed acceleration under a constant-acceleration model and initial velocity after removing the origin. Would a different constant origin remove the acceleration? Does the result establish a drag coefficient?

Course-specific review criteria

  • Use equal-time second differences with squared time units.
  • Recover the initial velocity rather than equating it with an interval average.
  • Separate rejecting a model from identifying a mechanism and propose an independent calibration check.

Include calculations with units, source or dataset provenance, assumptions, competing explanations and limitations as relevant. The draft is saved but is not a locked response until submitted.

0/3 responses retained. No recorded feedback exposure for this task version. Earlier versions may already be familiar. Public inspectability still prevents certification of unfamiliarity.

Retain a criterion-by-criterion human review

Reviewer identity and role are declarations, not authenticated credentials. Unsaved review fields below are lost on navigation. Review every criterion with an exact quotation, calculation or evidence citation and a next step.

College Physics I final evidence portfolio and model comparison

Submit a cumulative first report using these fixed packets: motion readouts 0.2, 1.3, 3.5 m at 0, 1, 2 s under xread=1.1x+.2; the 2 kg drive 6 N over 3 m then sticking 1 kg and spring k 12 packet; the taught drum at h 2 m, capture .5, with its idealized negligible-displacement terminal stop and no additional gravitational work; the taught pump at Q.2 L/s, eta.6; and an independent spring m 2, k 8 with indicated period 1.1pi s. Explain everyday motion/flow/thermal models without pretending synthetic records are observations of real equipment. Complete all six module evidence clusters and the separate cumulative mixed assessment.

  1. Freeze the measurement portfolio and recipient diagrams

    Record raw and corrected motion, unresolved between-frame distance, force diagrams and fixed unit/reference conventions. List which parameters are supplied, which are inferred and which observations genuinely test a prediction.

    Evidence to retain: Versioned first report, raw/calibrated table, recipient/system diagrams and exposure/assistance record.

  2. Reconcile staged conservation and constitutive models

    Carry drive work through the sticking collision and spring endpoint. Derive drum force/torque and interval energy accounts. Include a rejected contact, friction or material-domain alternative from the retained course investigations.

    Evidence to retain: Independent motion/work/momentum/rotation calculations, stage boundaries and a failed-branch explanation.

  3. Compare thermal-flow and oscillator explanations

    Close pump/fluid/exported/receiver powers and drum receiver energy. Contrast shared-clock oscillator inference with independent static evidence. Include one phase/entropy constraint and one wave-coherence or standing-mode comparison from the actual course tasks.

    Evidence to retain: Thermal and flow ledgers, calibration rival table, phase/second-law test and explicit wave model conditions.

  4. Retain critique and a reasoned revision

    A human reviewer cites concrete criteria and report passages, including one numerical or domain error or an explicitly justified no-error finding. Preserve the first report and critique before revision; identify every changed claim.

    Evidence to retain: Reviewer relationship and expertise limits, criterion-linked critique, first/revised reports and change rationale.

  5. Answer a genuinely frozen unfamiliar assignment

    The reviewer supplies actual new numerical observations spanning at least two modules, with a different calibration or physical-boundary issue and allowed resources. Freeze those details before the response and disclose public-key exposure or assistance.

    Evidence to retain: Immutable unfamiliar packet, response, independence declaration, criterion review and unresolved limitations.

Project review criteria

  • All six finite module clusters have concrete retained reasoning rather than links or completion ticks alone.
  • Units, frames, pressure/temperature references and calibration assumptions are consistent.
  • Forces, work, linear/angular momentum and thermal energy use explicit recipients and intervals.
  • Contact, material, fluid, phase, second-law and wave assumptions are checked where invoked.
  • Competing explanations are tested with an independently justified observation, not merely another sample sharing the same fault.
  • First report, criterion critique, revision and actual frozen unfamiliar response remain version-specific and auditable.
  • Authored coverage and self-reported completion are not equated with independent mastery, supervised technique, college credit or equipment safety.

Retain raw-data identifiers, provenance, units, prior predictions, methods, calculations, competing explanations and safety boundaries. State explicitly when data are simulated, supplied or genuinely observed. This saved text cannot verify a real experiment; do not invent measurements or completed supervised work. Maximum 12,000 characters; retain larger evidence files separately and cite them.

A nonempty report is only a saved submission. First and revised reports remain separate and cannot be overwritten. A critique of the first report is required before retaining one revision.

Fresh transfer direction

The human-frozen packet must include actual new numbers and at least two of mechanics/rotation, fluids/thermal, oscillator/waves plus a meaningful calibration or domain change. The public cumulative cases and a generic request to change a number are not independent transfer evidence. No physical apparatus is requested; authentic practical participation requires separately supervised opportunities.

A human must supply the actual new task, evidence and conditions before the learner responds. The transfer-direction text is not itself an unseen assessment. Use the retained assignment form after the first project; exposed public task identifier: expanded-public:college-physics1.

Science backups preserve each course's separate responses, exposure, rubric reviews and project history. Older backups do not reset attempts or erase known exposure. Divergent same-version immutable responses and incompatible same-version project histories are rejected rather than silently replaced; preserve both files for review.

Sources and boundaries
  • All 59 destinations in the declared finite six-module scope are authored. This is not a claim to cover every chapter of a textbook or to certify independently demonstrated course mastery.
  • No calculus is required. Software uses analytic turning points to disclose an invented hidden track, not to certify a unique reconstruction from sparse measurements.
  • The guided path is entirely virtual. No practical movement, machinery, water crossing, drop, launch, biological intervention or medical assessment is requested.
  • Independent learner understanding and supervised measurement technique require authentic evidence beyond public numerical checks and saved text.
  • No AP equivalency, college credit, practical competence or independently assessed mastery is awarded by page availability or self-reported completion.

Original LearnAI explanations and tasks use the references for scientific scope. Any attributed dataset or image has its own declared provenance. Laboratory or field activity requires an appropriate educator-approved protocol; no hazardous real-world operation is required by the guided path.

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