# Will someone check my work to see if Im on the right track?

1. Jul 22, 2013

### camel-man

This is collisions and momentum problem. for some reason it just seems like a short problem and im use to doing long problems so im here to check my work.

the questions is

A 50g bullet is fired vertically up at a 1.00 kg ballistic pendulum . The bullet strikes the block at
1000 m/s and emerges from it at 800 m/s. How far does the block rise? Assume that the
duration of the collision is instantaneous, in other words, during the collision no external forces
were acting on the system

Impulse given to block=0.050x1000-0.500x800=10=change in the block's momentum=1.00xv→v=10m/s. Using v²=u²+2as with v=0, u=10, a=-g=-9.8, we get 0=100-2x9.8s→s=5.1m.
[The collision isn't elastic but this doesn't matter since we aren't using energy conservation to solve the problem].

Am i missing something else?

2. Jul 22, 2013

### tiny-tim

hi camel-man!
looks ok to me

(though that's not how a ballistic pendulum works )