Question

croquet ball must have a set mass of 0.50 kg. a red ball moving at 10.0 m/s, strikes an at-rest green ball head on. The red ball continues moving at 1.5 m/s after it hits the green ball. What is the final speed of the green ball?

Answer 1

Use conservation of momentum:
m1u1+m2u2=m1v1+m2v2
m1=m2=0.5 kg
u1=10 m/s
u2=0 m/s
v1=1.5 m/s

Since m1=m2=0.5 kg, the masses can be cancelled out to give

u1+u2 = v1+v2
10+0 = 1.5 + v2
v2=8.5 m/s

Answer 2

15