The rotational velocity of a 45 rev/min phonograph record in rad/s is approximately
A) 45 rad/s.
B) 4.7 rad/s.
C) 0.75 rad/s.
D) 283 rad/s.
E) 15.7 rad/s.

Question

Quizplus · Accepted Answer

To convert revolutions per minute (rev/min) to radians per second (rad/s), use the conversion factor $2\pi \, \text{rad} = 1 \, \text{rev}$ and $1 \, \text{min} = 60 \, \text{s}$. Thus, $45 \, \text{rev/min} = 45 \times \frac{2\pi}{60} \, \text{rad/s} \approx 4.7 \, \text{rad/s}$.

The Rotational Velocity of a 45 Rev/min Phonograph Record in Rad/s