Physics
posted by Ace .
A solid disk rolls along the floor with a constant linear speed v.
(a) Find the fraction of its total kinetic energy that is in the form of rotational kinetic energy about the center of the ball.
Krot/Ktotal = ?

Total KE=rotaionalKE + linearKE
= 1/2 momentInertia*(v^2/r^2) + 1/2 mass*v^2 
The rotational KE is
(K.E.)rot = (1/2) I w^2
The angular velocity is w = V/R
The moment of inertia is (1/2) M R^2 for a solif disc.
Express (K.E.)rot in terms of M and V.
Then calculate
(K.E.)rot/[(1/2 M V^2 + (K.E.)rot]
That will be the answer.