Question

A 6.0-kg object moving 5.0 m/s collides with and sticks to a 2.0-kg object. after the collision the composite object is moving 2.0 m/s in a direction opposite to the initial direction of motion of the 6.0-kg object. determine the speed of the 2.0-kg object before the collision.

Answer 1

  m1v1 + m2v2 = (m1+m2)*(-vf) 
6*5 + 2*v2 = (6 + 2)*(-2) 
v2 = -16/2 = -8 m/s i