A solid disk, spinning counter-clockwise, has a mass of #1 kg# and a radius of #7 m#. If a point on the edge of the disk is moving at #3 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Mar 6, 2017

Answer:

The angular momentum is #=66kgm^2s^-1#
The angular velocity is #=2.69rads^-1#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=3ms^(-1)#

#r=7m#

So,

#omega=(3)/(7)*2pi=6/7pi=2.69rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=1*(7)^2/2=49/2kgm^2#

The angular momentum is

#L=2.69*49/2=66kgm^2s^-1#