Question

a 2 kg ball traveling at 5m/s collides with a 1 kg ball at rest. After the collision the 1 kg ball moves off with a speed of 7 m/s. Find the final speed of the 2 kg ball.

Answer 1

According to the Conservation of Momentum:

m1vo1 + m2vo2 = m1vf1 + m2vf2

2(5) + 1(0) = 2vf1 + 1(7)

10 + 0 = 2vf1 + 7

3 = 2vf1

vf1 = 3/2 m/s