At a certain instant, a compact disc is rotating at 210 rpm. What is its angular speed in rad/s?
A) 660 rad/s
B) 22 rad/s
C) 69 rad/s
D) 45 rad/s
E) 11 rad/s

Question

Quizplus · Accepted Answer

To convert revolutions per minute (rpm) to radians per second (rad/s), use the conversion factor $2\pi \, \text{rad} = 1 \, \text{rev}$ and $1 \, \text{minute} = 60 \, \text{seconds}$. Thus, $210 \, \text{rpm} = 210 \times \frac{2\pi}{60} \, \text{rad/s} = 22 \, \text{rad/s}$.

At a Certain Instant, a Compact Disc Is Rotating at 210