An object with a mass of 3 kg is traveling in a circular path of a radius of 15 m. If the object's angular velocity changes from 25 Hz to 34 Hz in 9 s, what torque was applied to the object?

1 Answer
Jan 10, 2017

The torque is =4241.2Nm

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 mass is I=mr^2

=3*15^2= 675 kgm^2

The rate of change of angular velocity is

(domega)/dt=(34-25)/9*2pi

=(2pi) rads^(-2)

So the torque is tau=675*(2pi) Nm=1350piNm=4241.2Nm