A solid disk, spinning counter-clockwise, has a mass of #6 kg# and a radius of #8/5 m#. If a point on the edge of the disk is moving at #12/5 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Feb 10, 2017

Answer:

The angular momentum is #=72.4kgms^(-1)#
The angular velocity is #=9.42rads^-1#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=12/5ms^(-1)#

#r=8/5m#

So,

#omega=(12/5)/(8/5)*2pi=3pi=9.42rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=6*(8/5)^2/2=192/25kgm^2#

#L=9.42*192/25=72.4kgms^(-1)#