Subject: Is there a formula for Inelastic Collisions where the objects do not stick?

I know there is a formula for perfectly elasic collisions where the objects 
collide and stick together moving off in the same direction. Is there a formula 
for inelastic collisions where one object collides and then penetrates the 
object but both objects move off in the same direction? For example if a 
bullets hits a penduluum that is at rest and then penetrates the penduluum 
causing it to move off in the same direction the bullet is going. Is there a 
way to figure out the speed of the pendulum immediately after the interaction 
with the bullet.

Re: Is there a formula for Inelastic Collisions where the objects do not stick?