An object with a mass of 8 kg is traveling in a circular path of a radius of 9 m. If the object's angular velocity changes from 4 Hz to 6 Hz in 8 s, what torque was applied to the object?

1 Answer
Apr 19, 2017

The torque was =1017.9Nm

Explanation:

The torque is the rate of change of angular momentum

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

The moment of inertia is =I

For the object, I=mr^2

So, I=8*(9)^2=648kgm^2

The rate of change of angular velocity is

(domega)/dt=(6-4)/8*2pi

=(1/2pi) rads^(-2)

So the torque is tau=648*(1/2pi) Nm=1017.9Nm