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 #15 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Dec 25, 2016

The angular momentum is #=720pi=2262kgm^2s^(-1)#
The angular velocity is #=(10pi)/3 =10.5rads^(-1)#

Explanation:

The angular velocity,

#omega=v/r=15/6Hz=5/3*2pirads^(-1)=(10pi)/3 rads^(-1)#

The angular momentum is

#L=Iomega#

Where #I# is the moment of inertia

For a solid disc, #I=1/2*m*r^2#

#I=1/2*12*6^2=216 kgm^2#

The angular momentum is

#L=216*(10pi)/3=(720pi)kg m^2s^(-1)#