# Homework Help: Momentum and motion question

1. Oct 21, 2007

### Rubi22

First post here on the forum, so excuse me for any mistakes.

A bullet of mass m is fired into a block of mass M initially at rest at the edge of a frictionless table of height h. The vullet remains in the block, and after impact the block lands a distance d from the bottom of the table. Determine the initial speed of the bullet.

No variables are given, the answer should be in the form of an equation.

I'm having a really hard time starting this problem, but am pretty confident that with a hint I could get it taken care of. I'm thinking that the conservation of momentum equation (Pi=Pf) will help determine the velocity of the bullet, but I'm not sure how to compensate for the block falling off of the desk. Maybe the laws of motion equation? (X=Xi+VixT+1/2AT^2)?

Any help would be appreciated. I have the answer from the book, but am not sure how to figure it out. Let me know if knowing the answer would help. Thanks

2. Oct 21, 2007