25-kg object traveling rightward at 2.0 m/s collides with a 0.30-kg object traveling leftward at 1.5 m/s. If they stick together, and the time…

A 0.25-kg object traveling rightward at 2.0 m/s collides with a 0.30-kg object traveling leftward at 1.5 m/s. If they stick together, and the time interval for the collision is 0.018 s, find (a) the joint velocity and (b) the magnitude of the average force that they exert on each other.