A solid disk, spinning counter-clockwise, has a mass of #5 kg# and a radius of #4 m#. If a point on the edge of the disk is moving at #7/3 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Jan 3, 2017

Answer:

The angular momentum is #=146.6kgms^(-1)#
The angular velocity is #=3.7rads^(-1)#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=7/3ms^(-1)#

#r=4 m#

So,

#omega=7/3*1/4*2pi=7/6 *pi =rads^(-1)#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=5*(4)^2/2=40kgm^2#

#L=14/12*pi*40=140/3*pi=146.6kgms^(-1)#