When a wheel is rolling without slipping, the magnitude of its velocity relative to the ground is greatest at
A) the point in contact with the ground.
B) the point at the center of the wheel.
C) the point at the top of the wheel opposite to the point in contact with the ground.
D) the point farthest forward from the center of mass of the wheel.
E) the point farthest behind the center of mass of the wheel.

Question

Quizplus · Accepted Answer

The velocity of each point on a rolling wheel can be broken down into two component velocities: the velocity of the center of the wheel and the velocity of the point relative to the center of the wheel. The magnitude of the velocity relative to the ground is equal to the vector sum of these two component velocities. At the point in contact with the ground, the velocity relative to the ground is zero because the point isn't moving relative to the ground. At the center of the wheel, the relative velocity also is zero because every point on the wheel is equidistant from the center and moving at the same angular velocity. The magnitude of the velocity relative to the ground is greatest at the opposite point at the top of the wheel, because the velocity of the point relative to the center of the wheel has a vector component that is equal and opposite to the velocity of the center of the wheel relative to the ground.

When a Wheel Is Rolling Without Slipping, the Magnitude of Its