An object with a mass of 3 kg is traveling in a circular path of a radius of 9 m. If the object's angular velocity changes from 2 Hz to 6 Hz in 8 s, what torque was applied to the object?

1 Answer
Apr 24, 2017

The torque was =763.4Nm

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=(3*(9)^2)=243kgm^2

The rate of change of angular velocity is

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

=(pi) rads^(-2)

So the torque is tau=243*(pi) Nm=763.4Nm