# What torque would have to be applied to a rod with a length of #4 m# and a mass of #4 kg# to change its horizontal spin by a frequency #7 Hz# over #1 s#?

##### 1 Answer

Feb 17, 2017

The torque is

#### Explanation:

The torque is the rate of change of angular momentum

The moment of inertia of a rod is

The rate of change of angular velocity is

So the torque is