RM01 / A MATTER OF PERSPECTIVE
Relative Motion Lab
One motion. Two observers. Build an explanation from evidence.
Your existing saved data has been preserved. Export it before replacing it. New work stays in memory until you choose a new record or import a valid record.
TODAY’S INVESTIGATION
Compare the same motion in two frames
How to use this lab
Choose a scenario. Read the given conditions and keep a first prediction, here or on paper. Observe the motion and record measurements. Then explain what your evidence shows. Changing conditions begins a new trial; changing a frame preserves the event and time.
East/right is positive in every view. x is position relative to the selected frame’s origin; displacement d = xf − xi. A/B means A relative to B. v̄ = d / Δt, where Δt is elapsed time. A frame with zero shore acceleration is inertial in this idealized model. Objects in that frame may still accelerate.
Reading, entering values, and leaving this tab pause the trial. Resume deliberately with Play. The model prescribes motion; it does not calculate forces, friction, or motor power. A trial with a passenger ends at the first deck-edge contact, without changing the prescribed velocity.
- 1 Predict
- 2 Observe
- 3 Explain
Display options
The trial starts paused. Graphs and readings appear only after observation.
Same instant, two descriptions
| Reference frame | x (m) | v (m/s) | a (m/s²) |
|---|
Passenger’s deck ruler
Compare graphs
Observe first. The graph never previews an unobserved interval.
Both graphs use the same scales. Color identifies the object; line styles and frame labels carry the same information. Saved velocity estimates use a dashed gray line.
Measure an interval
Enter interval times in the console. Displacement comes from position change; average velocity is displacement divided by elapsed time.
Events observed so far
Your trial record
Measurements are recalculated from each trial’s conditions. A first prediction remains attached to its original object and frames. Written work still needs teacher review.
| Trial / scenario | Observer / shore vi (m/s) | Object / frame | t (s) | x (m) | v (m/s) | a (m/s²) |
|---|