Bullet passing through block in ballistic pendulum

[hibachi7]

Homework Statement

A 8.15- g bullet from a 9-mm pistol has a velocity of 371.0 m/s. It strikes the 0.785- kg block of a ballistic pendulum and passes completely through the block. If the block rises through a distance h = 8.74 cm, what was the velocity of the bullet as it emerged from the block?


please, I'm having an extremely hard time figuring out how to even get started on this problem. my book does not help too much and my teacher is about 120 years old (J/k) thanks in advance

 

[saket]

the change in momentum of the bullet passes on to the block, which enables it to rise to the given height. now, i hope u can start off!