# A cylinder has inner and outer radii of #9 cm# and #14 cm#, respectively, and a mass of #9 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #1 Hz# to #7 Hz#, by how much does its angular momentum change?

##### 2 Answers

Change in angular momentum =

now,change in angular velocity=

So,change in angular momentum is

The change in angular momentum is

#### Explanation:

The angular momentum is

where

and

The mass of the cylinder is

The radii of the cylinder are

For the cylinder, the moment of inertia is

So,

The change in angular velocity is

The change in angular momentum is