If all of the objects illustrated in the figure have equal masses, the moment of inertia about the indicated axis is largest for the
A) ring
B) cross
C) sphere
D) cube
E) rod

Question

If all of the objects illustrated in the figure have equal masses, the moment of inertia about the indicated axis is largest for the
A) ring 
B) cross 
C) sphere 
D) cube 
E) rod

Quizplus · Accepted Answer

The moment of inertia for a solid sphere and cube are based on their mass distribution, which is mostly concentrated toward their central axis. The cross and rod have a smaller moment of inertia as their mass is distributed far from their central axis. The moment of inertia for a ring is given by MR^2, which is the largest among the given objects because it has all of its mass distributed at a distance R from the axis of rotation.

If All of the Objects Illustrated in the Figure Have