An object with a mass of 8 kg is traveling in a circular path of a radius of 12 m. If the object's angular velocity changes from 15 Hz to 6 Hz in 6 s, what torque was applied to the object?

1 Answer
Jan 25, 2017

The answer is =10857.3Nm

Explanation:

The torque is the rate of change of angular momentum

tau=(dL)/dt=(d(Iomega))/dt=I(domega)/dt

The moment of inertia of the object is I=mr^2

=8*12^2= 1152 kgm^2

The rate of change of angular velocity is

(domega)/dt=(15-6)/6*2pi

=((18pi)/6)=3pi rads^(-2)

So the torque is tau=1152*(3pi) Nm=3456piNm=10857.3Nm