Physics Collisions Level: Misc Level

A 3.0-kg object moving 8.0 m/s in the positive x direction has a one- dimensional elastic collision with an object (mass=M)initially at rest.After the collision the object of unknown mass has a velocity of 6.0 m/s in the positive x direction. What is M?

a. 7.5 kg

b.5.0 kg

c.6.0 kg

d.4.2 kg

e.8.0 kg