A solid disk, spinning counter-clockwise, has a mass of 6 kg6kg and a radius of 2 m2m. If a point on the edge of the disk is moving at 2/3 m/s23ms in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Mar 26, 2017

The angular momentum is =4kgm^2s^-1=4kgm2s1
The angular velocity is =0.33rads^-1=0.33rads1

Explanation:

The angular velocity is

omega=(Deltatheta)/(Deltat)

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

omega=v/r

where,

v=2/3ms^(-1)

r=2m

So,

angular velocity, omega=(2/3)/(2)=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=6*(2)^2/2=12kgm^2

L=I omega=12*0.33=4kgm^2s^-1