A solid disk, spinning counter-clockwise, has a mass of #14 kg# and a radius of #5/4 m#. If a point on the edge of the disk is moving at #2/9 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Feb 18, 2017

Answer:

The angular momentum is #=12.22kgm^2s^(-1)#
The angular velocity is #=1.12rads^-1#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=2/9ms^(-1)#

#r=5/4m#

So,

#omega=(2/9)/(5/4)*2pi=16/45pi=1.12rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

For a solid disc, #I=(mr^2)/2#

So, #I=14*(5/4)^2/2=175/16kgm^2#

#L=1.12*175/16=12.22kgm^2s^(-1)#