Mistake Master
Mistake Master · AP Physics 1 · Unit 4 · Step-Through Animation
Two Crashes, One Unbreakable Rule
You'll learnthat momentum survives every collision, while kinetic energy only survives elastic ones.
The same collision, filmed twice — once with spring bumpers, once with velcro. Watch the pink momentum bar shrug off both endings while kinetic energy meets a very different fate in each.
COLLISION LAB
Before you start
What you're looking at
Two lanes: a 2 kg cart at +4 m/s hits a parked twin, one pair on spring bumpers, the other on velcro.
The question
Both crashes conserve momentum, so what tells an elastic collision apart from an inelastic one?
Watch for
The momentum panel holding steady in both lanes while the energy panel diverges; predict which lane loses energy.
What the symbols mean
Momentum panel: pink bars per cart plus an outlined total; energy panel: K is kinetic, Eth is thermal.
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