Question

A 5kg object moves to the right with a speed of 2m/s. It collides in a perfectly elastic collision with a 2 kg object moving to the left at 5m/s.What is the total kinetic energy after the collision?

In elastic collisions KE is conserved so KE_i =KE_f
KE_f=1/2(5)(2)^2+ 1/2(2)(5)^2
=10+25
=35 J
Is this correct?

Answer 1

The toal Ke is the same as it started with, that is the definition of an elastaic equation.

Yes, you have it.