Two uniform cylinders have different masses and different rotational inertias.They simultaneously start from rest at the top of an inclined plane and roll without sliding down the plane.The cylinder that gets to the bottom first is:
A)the one with the larger mass
B)the one with the smaller mass
C)the one with the larger rotational inertia
D)the one with the smaller rotational inertia
E)neither (they arrive together)

Question

Quizplus · Accepted Answer

For rolling objects without slipping, the acceleration down an incline does not depend on mass or rotational inertia but on the shape (which determines the distribution of mass) of the object. Since both objects are uniform cylinders, they have the same shape factor in their moment of inertia calculation, leading to the same acceleration and thus, they reach the bottom at the same time regardless of their mass or rotational inertia differences.

Two Uniform Cylinders Have Different Masses and Different Rotational Inertias