A solid disk with a radius of 3 m and mass of 4 kg is rotating on a frictionless surface. If 60 W of power is used to increase the disk's rate of rotation, what torque is applied when the disk is rotating at 12 Hz?

1 Answer
May 15, 2017

The torque is =0.8Nm

Explanation:

Mass of disc =4kg

Radius of disc =3m

The power is related to the torque by the equation

P=tau *omega

P=60W

Frequency of rotation is f=12Hz

omega=f*2pi

angular velocity, omega=12*2pi rads^-1

torque, tau=P/omega

=60/(24pi)=0.8Nm