# Velocity of a bullet

1. Nov 7, 2009

### kubombelar

1. The problem statement, all variables and given/known data Hey guys here is my problem:
A bullet is fired horizontally into a wood block attached to a string,the bullet sticks in the block.Calculate the velocity of the bullet if the impact causes the block to swing 10cm above its initial level. Bullet=15g, Block=3kg,Height=10cm.

. Relevant equations]
Square root of 2gh (were g is acceleration due to gravity,h is height. j

2. Nov 7, 2009

### tiny-tim

Welcome to PF!

Hi kubombelar! Welcome to PF!

Start by using energy to find the initial velocity of the block.

Then use conservation of momentum.

3. Nov 7, 2009

### kubombelar

Hey thanks. using the formula i stated,i found 14.1ms and 1.4ms if i convert cm to m. Am i correct?

4. Nov 7, 2009

### tiny-tim

Hi kubombelar!

(what figure are you using for g?)
That's a weird way of putting it.

They can't both be correct, can they?

So which is it?
(and what do you then get for the velocity of the bullet?)