A solid disk, spinning counter-clockwise, has a mass of #2 kg# and a radius of #8/9 m#. If a point on the edge of the disk is moving at #11/4 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Dec 31, 2016

Answer:

The angular momentum is #=15.4kgms^(-1)#
The angular velocity is #=19.4 rads^(-1)#

Explanation:

The angular velocity is

#omega=v/r#

where,

#v=11/4ms^(-1)#

#r=8/9m#

So,

#omega=11/4/8/9=99/32*2pi =99/16pi=19.4 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=2*(8/9)^2/2=64/81kgm^2#

#L=64/81*99/16pi=44/9pi=15.4kgms^(-1)#