A solid disk with a radius of #9 m# and mass of #8 kg# is rotating on a frictionless surface. If #640 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 6, 2017

Answer:

The torque is #=6.79Nm#

Explanation:

mass of disc #=8kg#

radius of disc #=9m#

The power is related to the torque by the equation

#P=tau *omega#

#P=640W#

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

torque, #tau=P/omega#

#=640/(30pi)=6.79Nm#