The magnitude of the acceleration of an object moving in a circle at constant speed is
A) variable.
B) directly proportional to the speed squared.
C) directly proportional to the speed.
D) directly proportional to the radius of the circle squared.

Question

Quizplus · Accepted Answer

The magnitude of the acceleration of an object moving in a circle at constant speed is given by the formula $a = \frac{v^2}{r}$, where $v$ is the speed and $r$ is the radius of the circle. This shows that the acceleration is directly proportional to the square of the speed.

The Magnitude of the Acceleration of an Object Moving in a Circle