Question

Two spheres have the same radius and equal mass. One sphere is solid, and the other is hollow and made of a denser material. Which one has the bigger moment of inertia about an axis through its center?
a. Both the same.
b. The solid one.
c. The hollow one.

Answer 1

Answer:

Explanation:

Two sphere have same mass and radius but one is solid and another is hollow

Moment of inertia is the distribution of mass about the axis of rotation

For Hollow sphere more mass is at outside therefore its moment of inertia is more than solid sphere

$I_{hollow}=\frac{2}{3}mr^2$

$I_{solid}=\frac{2}{5}mr^2$