A 480-Kg Car Moving at 14

Multiple Choice

A 480-kg car moving at 14.4 m/s hits from behind a 570-kg car moving at 13.3 m/s in the same direction.If the new speed of the heavier car is 14.0 m/s,what is the speed of the lighter car after the collision,assuming that any unbalanced forces on the system are negligibly small?

A) 13.6 m/s
B) 10.5 m/s
C) 19.9 m/s
D) 5.24 m/s