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**1. Homework Statement**

A ballistic pendulum is used to measure the speed of a bullet fired from a gun. The pendulum consists of a 20.0g block hanging from a string. A bullet, with mass 0.50gg, imbeds itself in the block causing the block to swing up to a height of 5.00cm. Find the speed of the bullet as it leave the gun.

**2. Homework Equations**

W_nc = ΔK + ΔU

K = 1/2 mv^2

U = mgh

W = Fdcos∅

p = mv

**3. The Attempt at a Solution**

I wanted someone to double check my work, and if I used correct units or not.

pendulum

U = mgh

U = (20.0g)(9.8)(0.05cm)

U = 9.8 Joules (this is not gravity it is what mgh came out to)

bullet

K = 1/2 mv^2

9.8(U of pendulum) = 1/2(0.005)v^2

v^2 = 9.8/0.0025

v^2 = 3930

v = 62.6099

v = 62.6 m/s