A solid disk, spinning counter-clockwise, has a mass of #12 kg# and a radius of #6 m#. If a point on the edge of the disk is moving at #2 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Nov 28, 2016

The angular velocity #=1/3 Hz#
The angular momentum is #=72kgms^(-1)#

Explanation:

The angular velocity is

#omega=v/r#

Where #v=velocity=2ms^(-1)#

and #r=radius=6m#

So, #omega=2/6=1/3Hz#

The angular momentum is

#L=Iomega#

Where, #I=#moment of inertia

The moment of inertia of a solid disc is #=(mr^2)/2#

where, #m=# mass of the disc

#I=12*6*6/2=216kgm^2#

and #L=216*1/3=72kgms^(-1)#