Question

express the following angular speed in radians per second. 4 revolutions per second
the angular speed is radians per second. (type an exact answer in terms of $pi$.)

Explanation:

Step1: Recall conversion factor

One revolution is equal to $2\pi$ radians.

Step2: Calculate angular speed

If there are 4 revolutions per second, and 1 revolution = $2\pi$ radians, then the angular speed $\omega$ is $\omega=4\times2\pi$.
$\omega = 8\pi$ radians per second.

Answer:

$8\pi$