A solid disk with a radius of #9 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 #15 Hz#?

1 Answer
Mar 30, 2017

Answer:

The torque is #=5.09Nm#

Explanation:

mass of disc #=12kg#

radius of disc #=9m#

The power is related to the torque by the equation

#P=tau *omega#

#P=480W#

Frequency of rotation is #f=15Hz#

#omega=f*2pi#

angular velocity, #omega=15*2pi rads^-1#

torque, #tau=P/omega#

#=480/(30pi)=5.09Nm#