# A solid disk with a radius of 5 m and mass of 4 kg is rotating on a frictionless surface. If 3 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?

$\text{0.12 Nm}$ of Torque was applied on the disc.
$\text{Power = Torque × Angular Velocity}$
$\text{Torque" = "Power" / "Angular Velocity" = ("3 Watt") / ("2 π × 4 Hz") = "0.12 Nm}$