See figure, a constant horizontal force Fapplied of magnitude 10N is applied to a wheel of mass 7.6 kg and radius .52 m. The wheel rolls smoothly on the horizontal surface, and the acceleration of its center of mass (C.O.M) has magnitude 1.0 m/s^2. (a) What is the magnitude of the frictional force on the wheel? (b) What is the rotational inertia of the wheel about the rotation axis through the center of mass?

I have figured out part A to be 2.4 N.

By using the equation Fapplied - Ffriction = mass*acceleration

But im hung up on part B it is suppose to equal .6489 kg*m^2 but i cant get there.

http://home.earthlink.net/%7Ebaygentst/images/phys.GIF

Anybody?