A) Momentum is conserved:
On a frictionless horizontal air table, puck A (with mass 0.249 kg ) is moving toward puck B (with mass 0.371 kg ), which is initially at rest. After the collision, puck A has velocity 0.123 m/s to the left, and puck B has velocity 0.646 m/s to the right.
A) What was the speed Vai of puck A before the collision?
B) Calculate the change in the total kinetic energy of the system that occurs during the collision.