An 83.2-kg propeller blade measures 2.24m end to end. Model the blade as a thin rod rotating about its center of mass. It's initially turning at 175rpm. Find the blade's angular momentum, the tangential speed at the blade tip, and the angular acceleration and torque required to stop the blade in 12.0s.

Answer 1

C = pi*D = 3.14 * 2.24 = 7.04m = Circumference of circle formed by rotating blade.

V=175rev/min * 6.28rad/rev * (1/60min/s
= 18.32rad/s.

1. M = mV = 83.2 * 1.57 = 130.6 = Angular momentum.

2. V=175rev/min * 7.04m/rev * (1/60)min/s = 20.53m/s.

3. a = (Vf - Vo) / t,
a = (0 - 18.32) / 12 = -1.53rad/s^2.