A solid disk with a radius of #3 m# and mass of #12 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 #4 Hz#?

1 Answer
Mar 17, 2017

The torque is #=19.1Nm#

Explanation:

mass of disc #=12kg#

radius of disc #=3m#

The power is related to the torque by the equation

#P=tau *omega#

#P=480W#

angular velocity, #omega=4*2pi rads^-1#

torque, #tau=P/omega#

#=480/(8pi)=60/pi=19.1Nm#