What is the angular velocity of a 6–foot pendulum that takes 3 seconds to complete an arc of 14.13 feet? Use 3.14 for π.
45 degrees / second
pi/12 radians / second
pi/6 radians / second
85 degrees/second

Question

What is the angular velocity of a 6–foot pendulum that takes 3 seconds to complete an arc of 14.13 feet? Use 3.14 for π.
45 degrees / second
pi/12 radians / second
pi/6 radians / second 
85 degrees/second

anonymous · Answer

First find the central angle A in degree.
Perimeter circle  2Pi*R --> 360 deg
              Arc A = 14.13 --> x deg
(360*14.13)/2Pi*R = 5086.8/37.68 = 135 deg
The pendulum rotates 135 deg in 3 sec. Then, the angular velocity is : 135/3 = 45 deg/sec