A solid disk with a radius of 5 m5m and mass of 2 kg2kg is rotating on a frictionless surface. If 72 W72W of power is used to increase the disk's rate of rotation, what torque is applied when the disk is rotating at 4 Hz4Hz?

1 Answer
Harish Chandra Rajpoot
Jul 6, 2018

2.865\ \text{Nm}

Explanation:

frequency of rotation of solid disk is f=4\ Hz hence its angular velocity \omega is given as follows

\omega=2\pi f=2\pi\cdot 4=8\pi \ text{rad/s}

Now, the power P=72\ W imparted to the solid disk by applying torque T to create final angular velocity \omega=8\pi \text{rad/s} is given as follows

P=T\times \omega

T=P/\omega

=72/{8\pi}

=9/\pi

=2.865\ \text{Nm}

Related questions
See all questions in Torque
Impact of this question
1643 views around the world
You can reuse this answer
Creative Commons License