# Angular Velocity

An airplane propeller is rotating at $$1900$$rpm (rev/min).

(a)Compute the propeller’s angular velocity in rad/s.

(b) How many seconds does it take for the propeller to run through $$35^\circ$$?

Solution:

An airplane propeller is rotating at $$1900$$rpm (rev/min).

$$1$$rpm = $$2\pi /60$$$$\omega=(1900)(2\pi /60)=199$$Hence, the propeller’s angular velocity $$\omega$$=$$199$$rad/s.

b) $$35^\circ$$$$\pi/180^\circ$$=$$0.611$$rad.

Since angular velocity $$\omega$$=199rad/s, the time required for the propeller to run through $$35^\circ$$=$$\frac{0.611}{199}=3.1\times10^{-3}s$$