A solid disk, spinning counter-clockwise, has a mass of 9 kg and a radius of 6 m. If a point on the edge of the disk is moving at 2 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Mar 23, 2017

The angular momentum is =53.46kgm^2s^-1
The angular velocity is =0.33rads^-1

Explanation:

The angular velocity is

omega=(Deltatheta)/(Deltat)

v=r*((Deltatheta)/(Deltat))=r omega

omega=v/r

where,

v=2ms^(-1)

r=6m

So,

omega=(2)/(6)=0.33rads^-1

The angular momentum is L=Iomega

where I is the moment of inertia

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

So, I=9*(6)^2/2=162kgm^2

L=162*0.33=53.46kgm^2s^-1