# How far did it roll? Help!

1. Feb 2, 2010

### duckywucky

1. The problem statement, all variables and given/known data

In 1453, during the siege of Constantinople, the Turks used a cannon capable of launching a stone cannonball with a mass of 5.40 x 10^2 kg. Suppose a soldier dropped a cannonball with this mass while trying to load it into the cannon. The cannonball rolled down a hill that made an angle of 30.0° with the horizontal. If 5.30 x 10^4 J of work was done by gravity on the cannonball as it rolled down a hill, how far did it roll?

2. Relevant equations

3. The attempt at a solution

I know that you're looking for the distance traveled, obviously, but how do i get to that?!
KE = 1/2 mv^2?

2. Feb 2, 2010

### Staff: Mentor

The cannonball has two forms of KE. Linear KE (your formula that you listed), and rotational KE , which is influenced by the moment of inertia of the ball...

3. Feb 2, 2010

### duckywucky

So what formula would i use for the inertia of the ball?

4. Feb 2, 2010

### Staff: Mentor

You tell us! It's your class.