A solid disk with a radius of #7 m# and mass of #12 kg# is rotating on a frictionless surface. If #15 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
Apr 11, 2017

Answer:

The torque is #=0.64Nm#

Explanation:

Mass of disc #=12kg#

Radius of disc #=7m#

The power is related to the torque by the equation

#P=tau *omega#

#P=15W#

Frequency of rotation is #f=15Hz#

#omega=f*2pi#

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

torque, #tau=P/omega#

#=15/(30pi)=0.64Nm#