Posted by Megan on .
A 12.1 g CD with a radius of 6.16 cm rotates with an angular speed of 31.1 rad/s. What is its kinetic energy?

Physics please help!! 
drwls,
K.E. = (1/2) I w^2
I = (1/2) M R^2 = 2.30*10^4 kg m^2
w is the angular velocity in rad/s
The answer will be in Joules