MODULE 01 / CLASSICAL MECHANICS
Newton’s Laws
Discover how forces shape the way things move.
THE SECOND LAW
A force changes motion.
Change one variable. Make a prediction. Put it to the test.
Learning objective
Initial conditions · locked for this experiment
The cart experiment
ReadyHorizontal arrows show signed forces on a shared scale. Zero force has no arrow.
- Normal force FN
- N
- Max. static friction μsFN
- N
- Actual friction force
- N
- Net force
- N
Motion: · Friction regime:
The track spans −50 to +50 m. Each run ends at 6 s or at the first outward boundary crossing. The final velocity is retained; no collision is modeled.
Motion graphs
LIVESame data. Three perspectives.
Axes scale to measured values. Right edge = planned run end.
PREDICT → OBSERVE → EXPLAIN
Think before you press play.
Actual results
| Measurement | Run 1 | Run 2 |
|---|
The velocity graph overlays Run 1 (solid blue) and Run 2 (dashed orange) once Run 2 starts. Both curves use the same axes.
Reflect on the evidence
Instructor-authored model answer
On this horizontal track, the normal force balances weight: N = mg, g = 9.81 m/s². Net horizontal force is applied force plus signed friction force. With friction disabled, net force equals applied force. Positive x, velocity, acceleration, and force point right.