A solid disk, spinning counter-clockwise, has a mass of #7 kg# and a radius of #5 m#. If a point on the edge of the disk is moving at #6 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Jan 4, 2017

Answer:

The angular momentum is #=659.7kgms^(-1)#
The angular velocity is #=7.54rads^-1#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=6ms^(-1)#

#r=5m#

So,

#omega=6/5*2pi=12/5pi=7.54rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=7*(5)^2/2=87.5kgm^2#

#L=87.5*7.54=659.7kgms^(-1)#