Question

A uniform sphere of mass M and radius R placed on a smooth horizontal ground .the angular acceleration of sphere if force F is applied on it at a distance 7R/5 from ground level is

Answer 1

Answer:F/MR

Explanation:

By principal of moment,

( In the question it is not mentioned whether it is solid or hollow Sphere

I have done it by considering it a solid one)

Answer 2

Answer:

F/MR.

Explanation:

Since, the distance of the point is 7/5R from the center of the sphere. So, the moment of inertia of that point will be calculated as 2/5MR^2 + MR^2=7/5MR^2. We get this result by applying parallel axis theorem.

So, the torque T will be moment of inertia multiplied by angular acceleration a. So, the result will be T=M*a. T can be written as force*distance which is F*7/5R = 7/5MR^2*a. Now, a will be F/MR.