Learn Sixty-two original lessons implement Units 9–15: thermodynamics, electrostatics, circuits, magnetism/induction, geometric and physical optics, and modern physics. Two additional synthesis/project destinations complete the finite 64-destination authored scope, with a seven-unit cumulative assessment and retained capstone critique/revision/transfer workflow. Authentic learner and supervised practical evidence remain separate requirements.
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: AP Physics 1 or comparable mechanics, algebraic ratios, graph areas and scientific notation. Precalculus or equivalent is recommended by the framework. Guided thermal, electric, circuit, magnetic, optical and wave investigations require no programming or calculus.
Course outcome: Across the full seven-unit authored scope, connect microscopic motion with gas state data, audit thermal energy pathways, challenge measurement assumptions and distinguish conservation from qualitative second-law constraints; build electric vectors and scalar potentials, infer source charge and defend electrostatic energy boundaries, reconstruct circuit topology and infer source/device/transient properties under explicit measurement assumptions; connect magnetic source/force directions with flux-change polarity and mechanical/electrical energy closure; defend optical ray signs, focal and critical boundaries and multi-position inference; distinguish wave representations, interference boundaries and uncertainty-limited optical calibration; discriminate quantum energy and momentum models, close nuclear identity and mass-energy accounts, infer background-limited ensemble decay and defend a cross-domain subsystem capstone with critique and genuinely new transfer.
All lessons are directly accessible. Reused foundation explanations are identified where relevant; completing a different course does not award this course's evidence. The 64 registered lessons keep separate predictions, captures, practice responses and reflections.
Audit changing energy boundaries and shared calibration errors, select models across all seven units and retain an independently reviewed unknown-subsystem investigation.
Retain both gas constraints at 8 V, then repeat at 12 V. Freeze each stage ledger first, check the V² scaling and compare temperature rise, pressure/volume ratios and work signs. Reconstruct the complete source account without counting an intermediate transfer twice.
Compare scales 1,1; 1.1,1.2; and 0.8,0.8. Predict the whole-table ratio before reading. Retain the first explanation, then propose an external calibration or new controlled observation that separates at least two hypotheses without using the disclosed generator truth as evidence.
Compare photon and matter momentum, single-electron energy and spectral evidence; discriminate thermal/photoelectric models, close two-dimensional scattering and audit nuclear identity, mass-energy and background-limited decay inference.
Capture electron voltages 10, 40 and 90 V at one photon wavelength. Predict the wavelength ratios first; then vary only photon wavelength and explain why its energy scaling differs.
Compare n=1,2,4 at Z=1, then Z=1,2,3 at n=2. Retain radius, energy, wavelength and circumference ratio. Derive both scaling laws and identify one property this historical model does not establish.
Capture 3→2, 2→3 and 2→2. Predict emission, absorption or no energy-changing event before checking. Compare the ionization threshold from each initial state with the bound-to-bound gap.
Compare 3000 and 6000 K at one area, then double area at fixed temperature. Predict peak and total-power ratios. Retain the distinction among emitted, absorbed and net power and the finite plotting window.
At frequency control 8 compare powers 0, 1 and 2 nW; then compare frequency controls 4 and 8 at 2 nW. Retain missing values as missing and distinguish a count-rate change from a kinetic-energy change.
Compare angles 0, 90 and 180 degrees at 20 pm. Retain wavelength, both photon components, electron components and kinetic energy. Independently sum x and y momenta; then change incident wavelength at fixed angle to test what stays invariant.
Compare forward and reverse packets at additional energies 0, 10 and 20 MeV. Retain A, Z, signed Q and the final-energy screen. Contrast the fictional fission packet and state what the energy check cannot establish.
Hold one parent choice fixed and compare all four channels. Predict daughter A and Z and the emitted charge before checking. For each channel show where charge and nucleon number reside, then explain why the bookkeeping is not a stability prediction.
Compare backgrounds 0,20,40 at a fixed 4 min half-life, then compare half-lives 2 and 8 min. Retain raw and corrected counts, both fits and ensemble predictions. State an independent test for a drifting rather than constant background.
Connect kinetic theory, gas-state inference, thermal equilibrium, first-law paths, specific heat, conduction and qualitative entropy using original quantitative evidence.
Capture 300 K with masses 4 u and 40 u. Then retain 4 u and compare 300 K with 600 K. Explain the speed, energy and pressure ratios separately; use the distribution table rather than screen height alone.
Capture zero offset/no loss, then +6 kPa/no loss, then zero offset/20% final particle loss. Compare slopes, extrapolated zeros and residuals. Propose a separate measurement that distinguishes the two failure mechanisms.
Capture cold capacity 100 J/K at 300 K, then 200 J/K at the same temperature. Compare final temperatures and all three signed energy changes. Explain why the plotted approach rate is a separate assumption.
At final volume 4 L, capture all three paths. Calculate signed work-on and heat before reading their ledgers. Repeat at 5 L and explain why the difference between the low/high paths grows.
Capture constant-pressure and constant-volume cases at ratio 1.5, then constant-temperature and adiabatic cases at the same volume ratio. Reconstruct every ledger using ΔU=Q+Won. Do not compare the ratio labels as though all four control temperature.
Capture zero loss/zero offset, then 200 J loss/zero offset, then the same loss with +0.20 K offset. Compare the inferred values and reported bounds. Identify an independent check that separates compensating errors.
Capture B thickness 0.020 m with conductivity 0.20 W/(m K), then double conductivity. Separately double both B thickness and conductivity. Explain which pairs share resistance and which profile features differ.
Capture 8 particles with all-left and half-left counts, then repeat for 16 particles. Compare multiplicities and probabilities, not merely the location of the tallest plotted point. Explain why the total probability across all counts is one. Predict before checking: after the isolated hot/cold contact model reaches equilibrium, is total energy lower, and is its ability to drive an engine between those bodies unchanged? Also compare two paths between the same initial and final equilibrium states: can the system entropy changes differ?
Capture ratios 1.6/1.6 and reconstruct all four stage ledgers. Then change only pressure ratio and compare enclosed area, total positive heat and net work. Explain why zero net ΔU cannot be applied separately to every stage.
Conserve charge, infer Coulomb sources, resolve discrete-source fields, distinguish potential from field and audit pair/capacitor/particle energy under explicit constraints.
Retain transfer=4, redistribution=0 and transfer=4, redistribution=3. Check both the B subsystem sum and the composite sum. Then change transfer alone to 6 and identify which boundary charge crossed.
Capture source=3 at offsets 0 and 2 µN. Compare fitted charge, intercept and the nearest-reading estimate that ignores bias. Propose a separate check that could expose a wrong distance origin.
Retain equal-positive and equal-opposite source cases at height 0.30 m. Reconstruct both resultants from the table. Then change the height to 0.50 m without changing charges and compare actual magnitudes rather than rescaled screen lengths.
Capture r=0.05, 0.10, 0.15 and 0.30 m for Q=2 nC. Identify the interior plateau, continuous potential boundary and selected outside field limit. Reverse Q and track signs without changing magnitude.
Capture right charge −2 nC at x=−0.05, 0 and +0.05 m. Use the potential trend to predict the x field direction, then compare the component ledger. Change the right charge to +2 and identify which cancellation changes.
Retain side 0.20 and 0.40 m with third charge −1 nC. Check each pair and the total. Then use third charge −2 nC and explain why the total changes sign without a sign change in every pair.
Compare area 200 and 400 cm² at gap 2 mm, then compare gaps 2 and 4 mm at fixed area. Retain the numerical ratios and explain which boundary condition keeps voltage fixed.
Capture κ=3 in both boundary modes. Reconstruct ΔU=source work+external mechanical work. Repeat κ=1 to verify that no change yields zero work. State which quantities are constrained rather than discovered.
Compare +1 and −1 nC at 200 N/C, then zero charge. Retain the trajectory endpoint and both energy changes. Double field with the same charge and check linear displacement but quadratic kinetic-energy gain.
Conserve charge and energy in networks, distinguish source and meter effects, test ohmic assumptions and infer capacitor constraints and RC time scales.
Capture current 0.20 A at areas 0.5, 1.0 and 2.0 mm². Reconcile the identical charge-time slope with changing drift speed. Then increase current alone and explain which graph feature changes.
Compare lengths 1 and 2 m at area 0.20 mm². Record R and both powers, naming the source condition for every ratio. Then halve area and compare the result with doubling length.
Compare ohmic and nonlinear packets at zero offset. Record fitted slope, residual size and two interval slopes. Then add +0.20 V to the nonlinear packet and distinguish the shifted intercept from unchanged curvature.
Retain B=40 Ω closed and open. Reconstruct both current sums and complete source-power versus resistor-power balances. Draw the two node connections before interpreting the potential graph.
Compare voltmeter resistances 1, 2 and 10 kΩ at zero ammeter resistance. Then add 100 Ω series meter resistance. Explain both disturbances and reconcile the three current entries.
At r=2 Ω, compare loads 2, 8 and 20 Ω. Fit the terminal line from two points and verify the full power ledger for each. Separate the maximum-power observation from the efficiency trend.
Capture opposing emfs 4, 6 and 8 V at R₂=20 Ω. Reconstruct every node step, signed current and source power. Explain the zero-current middle case without assuming every element has zero potential difference.
Compare series and parallel at C₂=30 µF, recording charge, voltage and energy ledgers. Change C₂ to 10 µF and check whether the series equivalent remains below the smaller capacitance.
Required: compare R=2 and 4 kΩ in both modes, identify the 63%/37% time scales and describe initial/final voltages and current directions. Propose a trace feature that would expose a nonzero initial voltage. Optional enrichment: reconcile the numerical 0.20 s energy ledgers.
Distinguish dipoles, source fields and magnetic force; predict signed particle/current effects and reconcile Faraday–Lenz induction with energy conservation.
Capture 6 aligned dipoles at axis angles 0°, 60° and 180°, then compare the 4-against-4 case. Reconstruct the vector sum from the table and identify which conclusions concern this toy count model rather than a real material.
Compare positive and negative charge at speed 2×10⁵ m/s, then increase speed to 4×10⁵ m/s. Use the common spatial axis scale and numerical ledger, not the screen width across rescaled plots. Check the neutral straight-path limit.
Capture speeds 2, 3 and 4×10⁵ m/s for positive charge, then repeat for negative charge. Retain both force components and their sum. Finally test neutral charge and explain why it defeats a charge-identification claim.
Compare right currents +3 and −3 A at x=0, then repeat at x=+0.02 m. Reconstruct each signed contribution using its actual distance and explain the changed cancellation.
Capture angles 0°, 60°, 90° and 180° at +2 A. Draw segment and field directions for each. Reverse the current and verify which force signs reverse while magnitudes remain unchanged.
Compare 60°, 90° and 120° at the same area, then double area at 60°. Retain signed values and sketches of the normal. Explain what additional time information would be needed to calculate induced emf.
Capture 20 turns and ramp duration 0.20 s. Reconstruct all three interval polarities and currents. Double the turns, then separately double duration, explaining the emf and total resistor-heat changes using the declared 10 Ω assumption.
Compare speeds 1 and 2 m/s at 4 Ω, then compare resistances 4 and 8 Ω at 1 m/s. Retain current sign, drag, sustaining force and both powers. Use either the charge-force or flux-change route to check the emf magnitude.
Reconcile local-normal reflection, refraction and signed image formation; infer index and focal length from multiple observations while challenging reference and detection assumptions.
Compare normal tilts 0°, +5° and −5° at the same incident setting. Check both normal-relative angles and the outgoing page-relative angle. Explain how several differently tilted patches would produce diffuse reflection.
Retain object distances 20 and 40 cm at the same height. Follow each physical segment and its dashed backward extension. Compare image distance, height and the object-to-image separation.
Compare concave cases o=5, 10, 15 and 30 cm, then a convex case at 30 cm. Use the ray intersections or backward extensions to explain each sign and the exact focal boundary.
Compare indices 1.2 and 1.8 at the same 40° incident angle, then repeat at 0°. Retain angle, speed, frequency and wavelength; explain which quantities change and which do not.
Compare incidence 40° and 50° for destination index 1.0, then change destination index to 1.4. Explain why the total-internal-reflection state can disappear without changing the incident angle.
Compare converging cases o=5, 10 and 15 cm with the diverging case at 15 cm. Explain physical rays versus dashed extensions and why the focal-limit state cannot be replaced by a finite screen position.
Compare offsets 0, +1 and −1 cm at f=15 cm. Retain inferred focal length, slope and residuals. Explain a direct lens-plane calibration or independent geometry check that could challenge the offset hypothesis.
Compare objects at 20, 40 and 100 cm with the screen fixed at 20 mm. Retain required f, unchanged-lens image coordinate and geometric blur. Then move only the screen and explain which interpretation changes.
Connect wave snapshots and time traces, boundary phase and polarization, qualitative Doppler, superposition/resonance and uncertainty-aware diffraction/film inference.
Capture F=10 and 40 N at 4 Hz, then 40 N at 8 Hz. Predict speed, spatial spacing and temporal period before checking. Compare corresponding crests between the two snapshots while tracking the separate x=0 element.
Compare density-ratio choices 0, 2 and 4 at 4 Hz. Retain sign, width and both power fractions. Then double frequency at one boundary and identify which coefficients stay fixed and which wavelengths change.
Compare 0°, 45° and 90° with the same initial intensity, then change only intensity. Retain both stage outputs and explain the changed polarization direction between stages. Separately order visible red/violet by frequency without assigning different vacuum speeds.
Compare (source, observer) velocities (40,0), (0,40), (40,40) and (−40,0). Predict higher/lower/same pitch first. Use the optional spacing ledger to explain rather than memorize the signs.
Capture frequency differences 0, 2 and 4 Hz at zero phase, then compare 0 and 180° at equal frequency. Check several same-time coordinate rows by adding components yourself. Explain which changes alter beat spacing and which alter phase timing.
Compare all three boundary choices at mode index 2. Read displacement endpoints and, for air, pressure endpoints. Then compare indices 1–4 for the closed-open case and infer the spacing between allowed resonances.
Compare widths 2, 6 and 10 µm at 600 nm, then wavelengths 400 and 700 nm at one width. Retain exact angle, exact width and approximate width; flag comparisons outside the stated small-angle range.
Compare 2, 4 and 8 slits at 600 nm, then 400 and 700 nm at four slits. Retain first-order angle and the missing-order explanation. Distinguish peak narrowing from wavelength dispersion and from changes in normalized peak height.
Compare 0, 100 and 200 nm for each substrate choice. Retain top and bottom reflection reversals, optical path and net phase separately. Explain why the normalized equal-amplitude zero is not a measured zero-reflectance certificate.
Compare offsets −2, 0 and +2 mm at one wavelength; retain slope, intercept and the symmetric estimate. Then change wavelength and freeze a fourth-order prediction before reading its ledger value. Explain which calibration errors this comparison can and cannot remove.
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.
Evidence to retain: Retain both gas constraints, a changed source potential and three calibration pairs. Derive every stage account and challenge apparently independent agreement with a genuinely external reference plan.
Boundary: Original virtual endpoint and scale-error models; no physical circuit, heating or pressure operation. Numerical agreement is not practical validation.
Evidence to retain: Retain three momentum or level captures, derive changed-case ratios and challenge an atom-line interpretation using ionization and population boundaries.
Boundary: Single-electron levels and nonrelativistic matter momentum only; historical orbit is not an observed trajectory.
Evidence to retain: Freeze temperature/area and frequency/power predictions, retain a missing-cutoff case, fit an independent above-threshold line and propose a discriminating null-result check.
Boundary: Ideal blackbody and upper collection efficiency are stipulated, not apparatus calibration; no illumination or heating experiment.
Evidence to retain: Retain zero, oblique and backward-scattering captures; close both momentum components and photon/electron energy, explicitly preserving an undefined zero-vector direction.
Boundary: Initially stationary free electron; optional relativistic consistency calculation is supplied, not a physical X-ray exposure.
Evidence to retain: Audit signed mass-energy and particle ledgers, compare corrected and uncorrected synthetic rates, then infer a changed-case half-life with stated interval bounds.
Boundary: Fictional mass packets and generic decay identities do not predict isotope stability; no radiation source, dose or medical assessment.
Evidence to retain: Freeze spatial/temporal and phase predictions, retain contrasting recipes, test signed superposition and boundary power where supplied, distinguish pressure/displacement modes and challenge an ambiguous unshifted observation.
Boundary: Virtual, silent, linear models. Numerical Doppler, Malus projections and boundary coefficients are explicitly optional enrichment, not required formula recall or practical certification.
Evidence to retain: Retain predicted minima/orders and reflection-phase ledgers, distinguish exact and paraxial geometry, compare offset-canceling wavelength estimates and propagate declared independent length bounds before a held-out prediction.
Boundary: No laser or film activity. Normal-incidence film calculations only; normalized illustrative intensities are not measured reflectance, and a bounded parameter interval is not a confidence level.
Evidence to retain: Freeze local-normal and real/virtual predictions, retain three contrasting recipes including an exact focal boundary, reconcile signed distances with equal-scale ray diagrams and explain what a screen would detect.
Boundary: Original ideal geometrical rays and paraxial mirror/lens approximations; no lasers, sunlight focusing or physical optical alignment activity.
Evidence to retain: Retain multi-position observations, fit reciprocal or sine coordinates, challenge a common reference bias, classify critical-angle uncertainty and defend a changed fixed-screen prediction.
Boundary: Computed evidence, not measured glass properties or a clinical-eye assessment. Ray intensity, evanescent fields, diffraction and aberration are not modeled.
Evidence to retain: Retain coordinate/sign predictions, vector-component records, source-versus-force distinctions, orbit scaling and a competing explanation for a null deflection or field cancellation.
Boundary: Dipole bookkeeping is not a material magnetization law. Fixed hypothetical particles/wires, no strong magnets, high currents or beam apparatus.
Evidence to retain: Retain oriented normals, interval-by-interval flux/emf/current predictions, corner/closed-path assumptions and a mechanical/electrical power ledger under changed conditions.
Boundary: Computed uniform fields, piecewise-linear ramps and prescribed constant-speed rods; negligible inductance/friction declared, no authentic practical performance implied.
Evidence to retain: Retain a node schematic, prior branch-change prediction, fitted source/device data, signed loop/junction ledgers and a power account. Separate common offset, nonlinearity, source loss and meter disturbance.
Boundary: Virtual fixed-component networks and original synthetic packets. Nonideal-meter numerical correction is enrichment; no actual wiring, short circuit, heating or battery charging.
Evidence to retain: Retain initial middle-node charge assumptions, charge/voltage/energy ledgers, time-coordinate estimates and a competing explanation for a shifted or loaded trace.
Boundary: Ideal capacitors and qualitative/threshold time-constant inference; intermediate-time exponential calculations and time-dependent energy ledgers are optional enrichment, not measured RC hardware or proof of safe capacitor handling.
Evidence to retain: Retain a prior sign/component prediction, spatial data fit with intercept, vector ledger and scalar potential contrast. Challenge a calibration or boundary assumption with an independent discriminating check.
Boundary: Fixed hypothetical sources and synthetic sensor residuals. No charge-generation apparatus, grounding operation or physical field-mapping experiment is required.
Evidence to retain: Retain unique pair energies, capacitor geometry/unit conversions, fixed-Q/fixed-V comparisons and a trajectory versus energy cross-check. Include source and mechanical work when required by the selected boundary.
Boundary: Ideal point sources and parallel plates; no high-voltage, charged-capacitor or beam equipment. Browser evidence does not certify measurement skill or safety competence.
Evidence to retain: Retain predicted ratios, pressure readings and fitted slope/intercept, then distinguish a common pressure offset from changing particle inventory with an independent calibration proposal.
Boundary: Synthetic packets and ideal-gas assumptions; no pressurized vessel or extreme-temperature experiment is requested.
Evidence to retain: Draw the combined/subsystem boundaries, account for cup energy, propagate stated bounds and compare competing causes of a biased inferred material property.
Boundary: No actual heated samples, temperatures, conductivity measurement or practical competence is certified.
Evidence to retain: Use labeled diagrams, signed work/heat ledgers and changed conditions to separate end-state conservation from path dependence and allowed process direction.
Boundary: Quasistatic ideal-gas paths and a finite probability analogy. Supplied numerical engine limits are enrichment, not required AP entropy calculation.
Open the retained response and project workspaces. Practice, saved work and independently reviewed proficiency remain separate.
These 51 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.
An initially empty 0.010 F capacitor charges fully from an ideal 10 V source through resistance. After source disconnection, all stored energy is discharged, with 60% reaching an ideal monatomic gas. Find source expenditure, charging thermal conversion, gas heat and other discharge loss. For quasistatic constant-pressure gas heating, split heat into internal-energy gain and work by gas. Would reversing this numerical ledger alone establish a possible cyclic engine?
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.
Two equal positive point charges are fixed at x=−d and +d. Describe the midpoint field and potential using zero potential at infinity. A positive test charge displaced slightly right from the midpoint moves along the connecting line: give the initial force direction. Separately a 12 V ideal source drives a 2 Ω resistor in series with parallel 3 Ω and 6 Ω branches. Find source current, branch currents and total power. Explain why charge conservation at a junction does not imply equal branch currents.
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.
A positive charge enters a uniform +z magnetic field with velocity +x and no electric field. State force direction and whether its speed changes. Separately a 0.50 m conducting rod moves at 2.0 m/s perpendicular to a uniform 0.40 T field in an ideal closed loop of total resistance 2.0 Ω. Find emf magnitude, current, magnetic drag magnitude and required constant-speed mechanical power. State how Lenz reasoning selects current polarity.
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.
An ideal thin converging lens has focal length 12 cm. Compare object distances 18 cm and 6 cm: find signed image distance and magnification using 1/f=1/o+1/i and m=−i/o. What happens at o=12 cm? Separately light travels from index 1.50 into air; find critical angle from the normal and explain the equality boundary.
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.
Two equal coherent slits have separation 20 μm and use 600 nm light. Find the sine of the first noncentral constructive angle and the first destructive angle. If each slit width is 10 μm, which two-slit principal order first coincides with a single-slit zero? Explain why a missing principal order is not evidence that the photon frequency changed at the slit.
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.
A photoelectric surface shows no collected electrons. Give two distinct causes consistent with the result and a discriminating comparison. Separately a single-component detector records 450 then 250 counts/min four minutes later; independent constant background is 50 counts/min. Infer half-life and expected surviving fraction after twelve minutes. Explain why this cannot predict a particular nucleus’s decay 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.
For a capacitor-energy estimate using a voltage scale a and a calorimetric estimate using temperature-rise scale b, derive the estimate ratio. Evaluate a=0.9,b=0.81 at true energy2 J. Propose one external check and explain why repeating five voltages cannot resolve both scales. Specify what a reviewer must freeze before an unfamiliar transfer response.
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.
Two nonrelativistic electrons accelerated from rest through 16 and 64 V produce diffraction evidence. Find their momentum and wavelength ratios. For two photons of energies 16 and 64 eV, find the analogous ratios. Separately compare radius and binding-energy magnitude for a one-electron ion at n=2 when Z changes from 1 to 3. Explain why these numerical models do not establish literal electron orbits.
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.
Use hydrogen En=−13.6/n² eV. Find photon energy for 4→2 and the ionization threshold from n=4. An ideal thermal emitter separately warms from 3000 to 4500 K at unchanged area: find ratios of wavelength peak and emitted total power. Would equal selected photon wavelengths prove that a thermal continuum and an atomic line have the same production 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.
A supplied above-threshold calibration gives stopping magnitudes 0.5 V at 6×10¹⁴ Hz and 1.3 V at 8×10¹⁴ Hz. Infer slope, extrapolated threshold and work function in eV using the fitted line, not a separately rounded physical constant. Predict the cutoff change if power doubles at fixed frequency. A separate observation has zero collected current: give two distinct explanations and a discriminating comparison.
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.
A photon initially travels in +x with momentum 5×10⁻²³ kg m/s. After scattering its momentum magnitude is 4×10⁻²³ kg m/s at 60° above +x. An initially stationary free electron is the only other participant. Find its momentum components, magnitude and direction. Express the photon energy lost using c; explain why the supplied momentum pair must also satisfy the electron energy relation before being accepted as a physical event.
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.
For the same initial photon wavelength and an initially stationary free electron, compare Compton shifts at 60° and 120° using Δλ=λC(1−cosθ), where λC=h/(me c). Find their ratio and recoil y sign. Explain what happens to the recoil direction at zero scattering angle.
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.
A fictional nuclear reaction has total initial mass 12.015 u and final mass 12.020 u, with 6.0 MeV available center-of-mass kinetic/excitation energy. Use 931.494 MeV/u to find Q and final available energy. Separately a generic A=120,Z=60 parent emits alpha then beta-minus. Find final A,Z and total emitted charge. Does either calculation establish an actual decay rate?
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.
A claim says every radioactive decay must change the element. Compare alpha, beta-minus, beta-plus and gamma changes to generic parent A=80,Z=40. Explain how gamma emission can conserve energy and momentum while retaining A and Z, and why a balanced beta symbol does not prove that channel exists for a particular isotope.
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.
Two recorded rates are 330 and 180 counts/min six minutes apart, with fixed independently determined background 30 counts/min. Infer the half-life assuming constant efficiency and one component. In a different packet the corrected rates are 400±10 and 200±10 counts/min four minutes apart; bound the ratio and half-life using T=4 ln2/ln(ratio). Explain why these intervals do not schedule individual decays.
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.
An ideal string of mass per length 0.020 kg/m is under tension 18 N. A snapshot shows 5.0 m between adjacent crests. Infer propagation speed, frequency and period. If source frequency doubles while string properties stay fixed, predict the new wavelength. Explain why a marked string element need not travel 5 m with a crest.
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.
For two equal-tension ideal strings, an incident wave travels at 8 m/s and the second-string speed is 16 m/s. The source remains at 4 Hz. Predict reflection inversion and the two wavelengths. Optional supplied enrichment: r=(v2−v1)/(v2+v1), t=1+r, R=r² and T=(v1/v2)t². Use these to test a claim that transmitted amplitude greater than the incident amplitude creates 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.
A vertically polarized beam is blocked by an ideal horizontal analyzer. Inserting an intermediate analyzer at 45° produces nonzero output. Explain why this can occur without energy creation and why ordinary longitudinal sound is not polarized in the same manner. Compare red and violet light by vacuum speed, frequency and wavelength. Optional supplied projection law: Iout=Iin cos²θ; calculate final intensity for initial 12 W/m².
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.
In stationary air, a sound source stays to the left of an observer. Compare these constant subsonic cases qualitatively: source moves right with observer stationary; observer moves right with source stationary; both move right with the same velocity. Does the third case’s unshifted pitch prove that neither object moved? Explain why the sound formula should not automatically be reused for light.
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.
An ideal air column with speed 330 m/s has consecutive allowed resonances at 110, 330 and 550 Hz and is known to have one closed end and one open end. Infer its length and the harmonic labels. Identify pressure and displacement conditions at each end. A separate pair of tones at 330 and 334 Hz produces what beat rate? Explain why an antinode is not always at maximum displacement.
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An ideal coherent multiple-slit array has slit spacing 16 µm, slit width 4 µm and wavelength 640 nm. Find the first nominal interference angle and the first missing interference order. Find the exact central single-slit envelope width on a screen 1 m away. Explain whether the approximation 2Lλ/a is within the framework’s below-10° angle condition and whether normalized equal peak heights establish equal transmitted power.
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At normal incidence, 520 nm vacuum light reaches an index-1.30 film from air. Compare substrates of index 1.60 and 1.00. Find the quarter-wave film thickness and classify the relative phase of the two reflected contributions for each substrate. Explain why destructive relative phase alone does not certify zero actual reflectance.
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A separate small-angle packet has adjacent-order spacing s=2.640±0.020 mm, slit spacing d=0.250±0.002 mm and screen distance L=1.20±0.01 m. Use λ=sd/L to infer the central wavelength and conservative endpoint interval. Explain whether a common screen-coordinate offset changes s, and name a failure that the interval does not cover.
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A ray arrives at a horizontal plane mirror at 35° to the normal. The mirror rotates so its normal turns 6° away from the direction back toward the incoming source, increasing the incidence angle. Determine the new incidence angle and the change in reflected direction. Separately, a 3 cm object is 24 cm in front of an unrotated plane mirror. State signed image distance, image height and whether a screen behind the mirror can collect that image.
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An ideal thin converging lens has focal length +12 cm. Compare objects at 36 cm, 8 cm and exactly 12 cm. Calculate finite image distances and magnifications where they exist, classify each image, and explain why a missing screen image is not by itself proof of a broken lens. Compare the 36 cm object with a concave mirror of the same positive focal length.
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Light of vacuum wavelength 540 nm enters a stationary transparent material of index 1.50 from air at 30° to the normal. Use c=3.00×10⁸ m/s. Find transmitted angle, speed, frequency and wavelength. At a separate material-to-air interface, compare incidence at 40°, exactly the critical angle and 45°. Explain what an angle uncertainty of ±1° around 42° prevents you from concluding.
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An original air-to-material packet gives (sin incident angle, sin transmitted angle) pairs (0.30,0.20), (0.60,0.40) and (0.75,0.50). Infer the index using air index 1.00. Explain why a common angular zero error generally cannot be corrected by subtracting one constant from every sine value. Give an independent normal-reference check and a reason not to infer transparency or intensity from the fitted slope.
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An ideal converging lens is described by three original object/image distance pairs in cm: (30,30), (45,22.5) and (60,20). Infer focal length and the slope/intercept of a graph of 1/image distance against 1/object distance. A second record adds +1 cm to every image distance. Explain why its reciprocal graph is not simply shifted vertically by one constant, and propose a check that distinguishes a reference-position error from a changed lens.
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A thin lens must form a sharp paraxial image on a screen 25 mm beyond it. Compare required focal lengths for objects 50 cm and 25 cm in front. If the original 50 cm setting is retained for the nearer object, find the new image distance and say whether the screen lies before or beyond that focus. Explain why this calculation is not an eye prescription or a full prediction of real image sharpness.
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Eight equal dipole moments have five along +x and three along −x. Find the resultant in unit moments. All arrows then rotate together by 90° in the xy plane. Describe the new resultant and what happens if four point each way. Explain why cutting a real magnet cannot isolate a single pole and why this count model cannot predict material remanence.
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A hypothetical particle has mass 4×10⁻²⁷ kg, charge +2×10⁻¹⁹ C and perpendicular speed 3×10⁵ m/s in uniform B=0.30 T along +z. Entry velocity is +x. Find initial force direction, radius and whether kinetic energy changes. Separately choose a +y electric field that would cancel its magnetic force. Explain the effects of reversing charge and of replacing it by a neutral particle.
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Two long wires at x=±0.040 m each carry +4 A along +z. Find the magnetic field at the midpoint and the force per length between the wires using μ₀/(2π)=2×10⁻⁷ T m/A. Explain the change if the right current reverses. Distinguish the field observation point from the location where each wire feels force.
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A 40-turn coil has area 0.020 m² and its normal makes 60° with a uniform field. Field magnitude rises from 0.10 to 0.50 T in 0.20 s, then holds constant. The normal is oriented so the initial flux is positive. Find initial/final per-turn flux and average signed ramp emf. Give the plateau emf and explain the induced current direction relative to the chosen normal if the circuit is closed.
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A rod of length 0.50 m moves at constant 1.2 m/s along +x in uniform B=0.40 T along +z, expanding a rectangular closed loop of total resistance 6 Ω. Positive circulation is counterclockwise viewed from +z. Find signed emf/current, drag magnitude, sustaining power and heat in 10 s. Explain what extra term is needed if the rod is instead allowed to slow without a drive.
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A steady wire carries 0.25 A for 12 s. Find transported charge and explain whether a resistor downstream consumes part of that current. A second comparison doubles the length of a uniform wire without changing material or area: compare resistance and power ratios at fixed voltage versus fixed current. State the temperature assumption.
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An original packet gives 0.15, 1.25, 2.55 and 4.05 V at currents 0, 0.05, 0.10 and 0.15 A. Compare successive interval slopes and decide whether subtracting a common 0.15 V zero offset can make the response ohmic. Describe one independent check that could discriminate heating from a sensor artifact.
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An ideal 8 V source feeds 20 Ω in series with two parallel 40 Ω branches. Find source current, each branch current and each branch power. Open one branch and predict the surviving branch power. Qualitatively explain the effect of placing a finite-resistance voltmeter across the surviving branch and a nonzero-resistance ammeter upstream.
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A terminal-voltage plot gives 7.2 V at 0.4 A and 6.0 V at 1.0 A. Infer emf and internal resistance. Separately, a series loop has opposing ideal emfs 4 V and 10 V with total resistance 30 Ω. Choose positive traversal through the 4 V rise; find signed current, each source delivered power and resistor loss.
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Two initially uncharged capacitors 15 and 30 µF are placed in series across 12 V. Find equivalent capacitance, common charge, individual voltages and stored energy. Compare the equivalent capacitance and total energy if instead connected in parallel. State the middle-node condition used for the series reasoning.
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A discharging ideal capacitor begins at 10 V and falls to about 3.68 V at 0.40 s. R=4 kΩ. Estimate C and initial stored energy. Qualitatively explain why the remaining energy fraction is smaller than the remaining voltage fraction, and specify another observation that could expose a shifted time origin or nonzero baseline.
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Two initially neutral objects A and B exchange five electrons from A to B. Then two electrons shift from the right to the left part of B without leaving B. State QA, QB, the composite charge and whether polarization changes QB. Contrast this with allowing a ground connection. Explain why equal-potential connected conductors need not have equal charge.
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A +3 nC source at (−0.30,0) m and a −3 nC source at (+0.30,0) m produce a field at (0,0.40) m. With k=8.99×10⁹ N m²/C², calculate potential and both field components. Find force components on a −2 nC probe and explain why zero potential does not mean zero force.
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An original positive-probe experiment uses q=+5 nC. A fit of signed outward force against 1/r² gives slope 0.08990 µN m² and intercept +1.5 µN. Infer the point-source charge using k=8.99×10⁹ N m²/C². Explain why a nearest-reading inference without the intercept differs and propose an independent distance-calibration check.
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Charges +1, +2 and −2 nC form an equilateral triangle of side 0.30 m. With k=8.99×10⁹, calculate each pair energy and the total. All separations are then halved quasistatically. Find external and electric work for that change, and distinguish the scaling of pair energy from pair force.
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An ideal 80 pF capacitor starts at 15 V. A dielectric with relative permittivity 3 completely fills its unchanged gap. Compare final C, free plate charge, voltage and stored energy for disconnected versus connected conditions. For the connected case, close the field/source/mechanical energy ledger. Explain the opposing polarization field.
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A hypothetical −1 nC particle of mass 2×10⁻⁹ kg enters a uniform +y field of 400 N/C with vx=20 m/s and vy=0. The region is 0.040 m long. Neglect all other forces. Find transit time, exit y, ΔV and kinetic-energy change. State how to decide whether a finite plate gap invalidates that prediction.
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An original fixed-volume 3.0 L gas record has fitted pressure slope 0.300 kPa/K and a common +4.0 kPa sensor offset. Using R=8.314 J/(mol K), infer the fixed amount from slope, explain whether the offset changes that result, and propose evidence that could expose a slow leak. State why a fitted line alone is insufficient.
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A monatomic ideal gas with nR=1 J/K moves from (2 L, 120 kPa) to (5 L, 240 kPa). Compare expansion at the initial pressure followed by constant-volume heating with constant-volume heating followed by expansion at the final pressure. Find ΔU, work on the gas and heat into the gas for both paths.
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A 0.20 kg sample cools by 25 K. Water gains 1800 J and the cup gains 200 J. An analysis that assumes no other transfers gives one specific heat. A second hypothesis adds a 400 J external loss. Calculate both values and propose a controlled measurement that can distinguish the hypotheses rather than merely averaging the two estimates.
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Two ideal layers in series have thermal resistances 4 and 6 K/W between boundaries at 320 and 300 K. Find steady power and the interface temperature after the first layer from the hot side. Separately explain how a warmer object can heat a cooler one across an evacuated gap, and why rising warm air is a different transfer mechanism.
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In the original four-particle equal-compartment model, compare exactly two particles on each side with all four on one specified side. Separately, a proposed cyclic device absorbs 800 J from one reservoir, rejects no heat and delivers 800 J work. Explain which law its energy ledger satisfies and why that alone does not make the proposal possible.
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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.
Characterize the supplied unknown electrical subsystem, then defend a seven-unit evidence portfolio that connects thermal, field, circuit, magnetic, ray, wave and quantum reasoning. Original core packet: terminal observations (current A, potential V) are (0.10,5.80), (0.20,5.60), (0.30,5.40), with each potential bounded by ±0.02 V and currents stipulated exact. Candidate models include an ideal source, an emf with internal series resistance, or a biased voltage reference. These synthetic observations support a bounded model, not an actual device or real apparatus rating. Optional optical alternative: object/image distances (30,60) and (40,40) cm in a thin-lens packet, with ±0.5 cm reading bounds; challenge a common distance-scale or origin error before claiming a calibrated focal length. Earlier project versions remain historical, not silently regraded. Completing a report is not passing independent review.
Choose the electrical core or optical alternative. Record at least two competing models, predicted observations, reference conventions and one proposed discriminating observation before calculating. Limit the first plan to three primary observations plus one independent check.
Evidence to retain: Immutable prior plan, original supplied packet, declared reading bounds and explanation of why the independent check adds information rather than repeats the same calibration.
For the electrical core infer emf and internal resistance from terminal-current evidence, compare the ideal-source alternative and predict a fresh current before checking. For the optical alternative infer focal length from both positions and challenge shared reference error. Retain algebra, units and bounded alternatives; do not turn interval limits into confidence levels.
Evidence to retain: At least two independent calculations within the packet, an explicit allowed parameter range or conservative sensitivity bound, a held-out prediction and an unresolved-model statement.
Use the source-capacitor-gas synthesis with two constraints and a changed source potential. Independently reconstruct charging expenditure, storage, discharge leakage, heat, work-on and gas internal energy. Contrast a zero field with nonzero potential and a fixed-charge/fixed-voltage capacitor comparison from the earlier portfolio.
Evidence to retain: At least three retained recipes; separate stage ledgers; no double counting; qualitative entropy condition; signed vector/scalar and capacitor-source boundary reasoning.
Retain a charged-particle or crossed-field null comparison and a rod or flux-change induction account. Specify axes and loop normal, challenge at least two causes of a null and close the mechanical/electrical energy ledger.
Evidence to retain: Vector direction, missing or zero observations distinguished, signed flux slope and a power balance with limitations.
Retain a real/virtual or critical-angle boundary and a two-slit, diffraction or normal-incidence film inference. Explain when rays suffice, when phase is essential and what geometry/calibration uncertainty limits the result.
Evidence to retain: Ray/sign prediction, exact focal or grazing boundary, optical path/phase calculation, raw coordinates and a changed-case inference. Clearly identify optional intensity formulas.
Use a photoelectric/spectral contrast and a two-dimensional Compton account, then audit one nuclear mass/identity packet and a background-corrected decay inference. Retain an undefined or null case rather than inventing an observation.
Evidence to retain: Frequency versus rate distinction, energy and both momentum components, signed mass-energy and charge/nucleon balance, ensemble estimate and stated background limits. Generic nuclear bookkeeping is not an isotope-stability measurement.
Submit the first full report, then have a human critique every listed criterion using exact quotations or calculations and targeted next steps. Preserve one revised report after critique, explicitly linking each change to the evidence rather than overwriting the first explanation.
Evidence to retain: First report, declared reviewer identity and relationship, criterion-specific judgments and citations, and separate revision. Reviewer declarations do not authenticate expertise or independence.
A human supplies a genuinely new subsystem packet and one changed cross-domain constraint with actual numerical observations, provenance, allowed resources and conditions. Freeze it before the learner responds; preserve known exposure and then review the new response.
Evidence to retain: Actual immutable assignment, declared independence/exposure, retained response and review. A template direction, relabeled public task or missing assignment is not unfamiliar transfer.
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.
Supply new numerical terminal-current or multi-position optical evidence with a different calibration ambiguity, and an added thermal, magnetic, interference or quantum observation that discriminates two explanations. Freeze the actual prompt, observations, measurement bounds, provenance, resources and conditions before responding. Do not reuse the public packet or merely change its title. Preserve a response and a criterion-level human review. A supervised practical extension requires a separately approved safe local protocol; no physical operation is authorized by this virtual project.
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:ap-physics2.
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