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 1 Hz to 5 Hz in 5 s, what torque was applied to the object?

1 Answer
Oct 11, 2017

The torque was =60.3Nm

Explanation:

The torque is the rate of change of angular momentum

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

where I is the moment of inertia

The mass of the object is m=3kg

The radius is r=2m

For the object, I=mr^2

So, I=3*(2)^2=12kgm^2

And the rate of change of angular velocity is

(d omega)/dt=(Deltaomega)/t=(10pi-2pi)/5=(8/5pi)rads^-2

So,

The torque is

tau=12*8/5pi=60.3Nm