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 centre 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 centre of mass of the wheel.
E)the point farthest behind the centre of mass of the wheel.

Question

Quizplus · Accepted Answer

When a wheel is rolling without slipping, the point on the top of the wheel opposite the point in contact with the ground (referred to as the "top dead centre" point) has the greatest magnitude of velocity relative to the ground because it is moving with the linear velocity of the wheel, as well as the rotational velocity of the wheel around its axis. At this point, the linear velocity is directed vertically upward, while the rotational velocity is directed horizontally forward, resulting in a vector sum that has a greater magnitude than the velocity at any other point on the wheel.

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