A solid disk with a radius of 2 m and mass of 8 kg is rotating on a frictionless surface. If 480 W of power is used to increase the disk's rate of rotation, what torque is applied when the disk is rotating at 18 Hz?

1 Answer
Feb 28, 2018

The torque is =4.24Nm

Explanation:

Apply the equation

"Power (W)" ="torque(Nm)"xx"angular velocity" (rad s^-1)

The power is P=480W

The frequency is f=18Hz

The angular velocity is

omega=2pif=2xxpixx18=(36pi)rads^-1

Therefore,

The torque is

tau=P/omega=480/(36pi)=4.24Nm