A solid disk, spinning counter-clockwise, has a mass of #4 kg# and a radius of #1/2 m#. If a point on the edge of the disk is moving at #6/5 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Feb 27, 2017

Answer:

The angular momentum is #=7.54kgm^2s^-1#
The angular velocity is #=15.08rads^-1#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=6/5ms^(-1)#

#r=1/2m#

So,

#omega=(6/5)/(1/2)*2pi=24/5pi=15.08rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=4*(1/2)^2/2=1/2kgm^2#

#L=15.08*1/2=7.54kgm^2s^-1#