# Rotational Energy

1. Jul 23, 2008

### Lance WIlliam

A 250 g baseball is pitched at 35 m/s, and it's spinning at 55rad/s .

What fraction of its kinetic energy is rotational? Treat the baseball as a uniform solid sphere of radius 3.8 cm.

What the?! Im pretty lost on this one....

Do I use K_rot_=(1/2)$$I$$$$\omega$$^2

2. Jul 23, 2008

### rock.freak667

Yes this will give the rotational ke of the ball.

3. Jul 23, 2008

### Lance WIlliam

What is the Fraction of KE though?

4. Jul 23, 2008

### rock.freak667

The total energy of the ball is $\frac{1}{2}mv^2$