# A solid disk with a radius of #9 m# and mass of #4 kg# is rotating on a frictionless surface. If #750 W# of power is used to increase the disk's rate of rotation, what torque is applied when the disk is rotating at #4 Hz#?

##### 1 Answer

Jun 23, 2017

The torque is

#### Explanation:

The mass of the disc is

The radius of the disc is

The power and the torque are related by the formula

The angular velocity is

The power is

Therefore,

The torque is