A wheel is rolling (without slipping) on the ground. Its axle travels at 30 m/s with respect to the ground. The instantaneous speed (with respect to the ground) of a point on the rim directly above the axle is
A) 15 m/s.
B) 30 m/s.
C) 45 m/s.
D) 60 m/s.
E) 90 m/s.

Question

Quizplus · Accepted Answer

The point on the rim directly above the axle moves at twice the speed of the axle, so its speed is 60 m/s.

A Wheel Is Rolling (Without Slipping) on the Ground