A solid disk, spinning counter-clockwise, has a mass of 6 kg and a radius of 3/2 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
Feb 27, 2017

The angular momentum is =84.8kgm^2s^-1
The angular velocity is =12.57rads^-1

Explanation:

The angular velocity is

omega=v/r

where,

v=3ms^(-1)

r=3/2m

So,

omega=(3)/(3/2)*2pi=4pi=12.57rads^-1

The angular momentum is L=Iomega

where I is the moment of inertia

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

So, I=6*(3/2)^2/2=27/4kgm^2

L=12.57*27/4=84.8kgm^2s^-1