I have this question which I cant solve, could anyone lend a hand?

A ball of radius R, mass M, and moment of inertia 2/5MR^2 is placed on a plane inclined at an angle θ. The plane is accelerated upwards (along its direction) with acceleration a, as shown. For what value of a is the center of mass of the ball stationary? Assume sufﬁcient friction so that the ball does not slip.

http://i.imgur.com/9kEowYm.png

Question

I have this question which I cant solve, could anyone lend a hand?

A ball of radius R, mass M, and moment of inertia 2/5MR^2 is placed on a plane inclined at an angle θ. The plane is accelerated upwards (along its direction) with acceleration a, as shown. For what value of a is the center of mass of the ball stationary? Assume sufﬁcient friction so that the ball does not slip.

http://i.imgur.com/9kEowYm.png

anonymous · Answer

just calculate the acceleration of the rolling sphere if the plane was not accelerated..

once you do taht.. you keep the sphere's CM stationary, you need to move the plane up with the same value right?