A solid disk with a radius of #5 m# and mass of #3 kg# is rotating on a frictionless surface. If #45 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
Apr 19, 2017

Answer:

The torque is #=1.43Nm#

Explanation:

Mass of disc #=3kg#

Radius of disc #=5m#

The power is related to the torque by the equation

#P=tau *omega#

#P=45W#

Frequency of rotation is #f=5Hz#

#omega=f*2pi#

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

torque, #tau=P/omega#

#=45/(10pi)=1.43Nm#