A solid disk with a radius of #6 m# and mass of #8 kg# is rotating on a frictionless surface. If #18 W# of power is used to increase the disk's rate of rotation, what torque is applied when the disk is rotating at #5 Hz#?

1 Answer
Mar 28, 2017

The torque is #=0.57Nm#

Explanation:

mass of disc #=8kg#

radius of disc #=6m#

The power is related to the torque by the equation

#P=tau *omega#

#P=18W#

Frequency of rotation is #f=5Hz#

#omega=f*2pi#

angular velocity, #omega=5*2pi rads^-1#

torque, #tau=P/omega#

#=18/(10pi)=0.57Nm#