Question

A 1622 kg car has a speed of 11.3 m/s when
it hits a tree. The tree doesn't move and the
car comes to rest.
Find the change in kinetic energy of the car. .
Answer in units of J.

Answer 1

KE = 1/2mv^2
1/2(1622)(11.3)^2 = 103557 J when the car hits the tree.
But since the car came to a stop, there is no motion, no kinetic energy