posted by Jim on .
Consider a perfectly inelastic head-on collision between a small car and a large truck traveling at the same speed. Which vehicle has a greater change in kinetic energy as a result of the collision?
Since the vehicles stick together after the collision and take the direction of the large truck (greater momentum), I guessed that the small car would have a greater change in kinetic energy.
I can easily use formulas to find answers, but I always have trouble with conceptual questions like this.
Hmmmm. What is a perfectly inelastic collision as compared to an inelastic collision?
Momentum is conserved.
Mv-mv= initial momentum
after the collision...
now which is greater?
v-v', or -v-v' Obviously, the smaller mass is greater (-v-v').