Defend a bounded transport design
Compare predicted stopping, energy and power, then test a design against conservative bounds.
Prepare with stopping-energy evidence and momentum and impulse. This virtual evidence does not replace supervised practical work.
Design brief: a virtual tabletop transporter
Recommend a cart carrying a fragile fictional payload across a level track, then braking to rest within 0.40 m. Entry speed must be at least 0.60 m/s. The chosen mass includes cart and payload. The same design must also stop within 0.40 m after an additional 0.10 kg payload is added, with unchanged entry speed and brake force. Compare at least two different recipes; you have six retained trials. These are simulated teaching constraints, not a safe construction specification.
Assume constant horizontal braking force, no other horizontal forces, no rotation, and a nonnegative speed until rest. All initial kinetic energy becomes thermal energy in the cart/track system. Use g only if needed in your explanation; this model does not calculate a friction coefficient or motor operation.
Assigned conservative bounds are mass ±0.01 kg, entry speed ±0.02 m/s and brake force ±0.02 N. These are stipulated bounds, not confidence intervals. A robust recommendation must meet stopping distance for both original and increased load at maximum mass/speed and minimum force, and the speed requirement at minimum speed. A nominal pass alone is insufficient.
Original model values; no physical measurements or hardware instructions. Do not build, power or launch apparatus from this activity. A supervised real practical would require a separate risk assessment.
Predict, then retain a recipe
0/6 trials retained. Results are revealed only when the prediction is saved. The public model can be inspected; this is not an unseen examination. Reopening or importing work does not refund a recorded trial.
Construct a defensible report
Reconcile Fd = ½mv² with Ft = mv and distinguish average from peak power. Explain why doubling speed quadruples the distance but doubles the stopping time at fixed mass/force. Cite specific trial recipes, then test your chosen design against the bounds.
Saving checks only two distinct recipes and nonempty report fields. It does not verify calculations, causality, writing quality or independent practical competence.
The first snapshot is retained permanently. After critique, save one separate revision; further work can be exported for offline review.
Review and independent transfer
- Check units, energy boundary, signed impulse and constant-force assumptions.
- Identify the controlled comparison and whether the cited results support the claim.
- Recalculate the bounding case, including the minimum entry speed requirement.
- Explain a failure mode outside this model: varying force, wheel rotation or payload motion, for example.
- Request a new case with a different force law or uncertainty bounds. Repeating this exposed model is practice, not independent evidence.
A reviewer should identify evidence and a revision for each criterion. A completed report is not a claim that a learner has performed a physical investigation.
Relationships checked 30 October 2026: work–energy theorem and impulse. All case prose and values are original.
Science backup includes recipes, predictions, drafts and saved reports. Imports preserve known trials and reject incompatible prediction histories or combined histories exceeding six trials.
Save a science backup or import one
Science work is stored locally in this browser, separately from mathematics and AI. It does not sync automatically. Use this science-only backup; this checkout's older all-subject export does not include science.
A legacy file is available only when the complete snapshot fits the 36 MB limit. For larger snapshots, prepare a complete file set below; never discard notebooks to make a smaller file.
Matching imported notebook drafts replace their current drafts. Omitted lessons and known first attempts remain. Export your current work first if you want to retain both drafts.
Complete file sets and course backups
A file set can hold more work than one science file. Keep its manifest and every part together. Each file is limited to 36 MB. This format needs this version of LearnAI or a compatible newer version; older versions can use only the legacy single-file backup above.
The set includes every saved science course and global continuation at this moment. Later edits need a new export. A conflicting tab exports its own visible work, which may differ from saved work in another tab.
0 file(s) selected. File order and filenames do not determine identity. Missing, changed or conflicting parts block the entire restore; no good part is applied by itself.
Science storage: loading. No account or remote computation is required.