The angular speed of the hour hand of a clock, in rad/s, is
A) .
B) .
C) .
D) 1 800π.
E) 7 200π.

Question

The angular speed of the hour hand of a clock, in rad/s, is
A) . 
B) . 
C) . 
D) 1 800π. 
E) 7 200π.

Quizplus · Accepted Answer

The hour hand of a clock completes one revolution in 12 hours or $2\pi$ radians in 12 hours. 
Therefore, the angular speed of the hour hand is:
$\omega = \frac{2\pi}{12	ext{ hours}} = \frac{\pi}{6	ext{ hours }}$
$= \frac{\pi}{6	imes 60 	ext{ minutes }} = \frac{\pi}{360 	ext{ minutes }}$
$= \frac{\pi}{21 600 	ext{ seconds}}$
$= \frac{1}{3600}\cdot \frac{\pi}{6}$
$= \frac{1}{6\cdot 3600}\cdot \pi 	ext{ rad/s}$
$= \boxed{11eb6adc_eeaf_ccb9_b0cf_65ad99964954\_TB8245\_11}$ (B)

The Angular Speed of the Hour Hand of a Clock