An object with a mass of 3 kg is traveling in a circular path of a radius of 2 m. If the object's angular velocity changes from 2 Hz to 17 Hz in 5 s, what torque was applied to the object?

1 Answer
Jan 5, 2017

The torque is =226.2Nm

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

=3*2^2= 12 kgm^2

The rate of change of angular velocity is

(domega)/dt=(17-2)/5*2pi

=(6pi) rads^(-2)

So the torque is tau=12*(6pi) Nm=72piNm=226.2Nm