A 250-Kg Object Sitting at Rest Is Struck Elastically in a a Head-On

Multiple Choice

A 25.0-kg object sitting at rest is struck elastically in a head-on collision with a 20.5-kg object initially moving at +4.0 m/s.Find the final velocity of the 25.0-kg object after the collision.

A) −0.90 m/s
B) −3.6 m/s
C) +6.6 m/s
D) +3.6 m/s
E) +15 m/s