🧭 Plot Summary
In Activity 5-1-3 you found that momentum survives a collision, even when the carts stick and a big share of the kinetic energy vanishes. That raises a question: is every collision like that? Not quite. A pair of magnets that repel, or two billiard balls, bounce apart and keep nearly all their kinetic energy. Two cars that lock together keep almost none of the energy they started with.
Momentum is conserved in all of them. The energy is what tells the types apart. You’ll crash carts with three kinds of bumper, score each collision, predict what happens when the masses are unequal, and then follow the missing energy into the crumpled metal of a car crash.
What you will do in this activity
- Learn the three kinds of collision and how to tell them apart by what happens to the energy.
- Crash carts together with three different bumpers and measure the momentum and kinetic energy before and after.
- Calculate how much kinetic energy each collision lost, and a number that scores how bouncy it was.
- Predict, then test, what happens when a heavy cart hits a light one and a light cart hits a heavy one.
- Follow the lost energy into a car crash, a preview of Problem 5-3-1.
Why it matters
Knowing which kind of collision you have tells you which equations to use. It also tells you how much energy went into damage, which is how investigators work backward from a wreck in Problem 5-3-1.
✅ Self-Check Before You Roll On
Check off each item as you get there. These are not grades — they are your own signal.