Question

A 1500 kg car moving east at 15 m/s collides with a 1730 kg car moving south at 15 m/s and the two cars stick together. What is the velocity of the cars right after the collision?
How much kinetic energy was converted to another form during the collision?

Answer 1

Momentum, a vector, is conserved. Work conservation of momentum in E, and then in S directions.