Question

A red 120 kg bumper car moving at 4 m/s collides with a green 100 kg bumper car moving at 3 m/s. The red bumper car bounces off at 2 m/s. What is the green car's final velocity?​

Answer 1

we can utilize the equation pi=pf (p=momentum). because p=mv, we can sub in the initial masses and velocities as well as the finals in order to form an equation. this results in 120(4)+100(3)=120(2)+100x. this can be simplified to 540=100x, or x=5.4 m/s.