A solid disk, spinning counter-clockwise, has a mass of 3 kg3kg and a radius of 8/3 m83m. If a point on the edge of the disk is moving at 11/4 m/s114ms in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
May 31, 2018

The angular momentum is =11kgm^2s^-1=11kgm2s1 and the angular velocity is =1.03125rads^-1=1.03125rads1

Explanation:

The angular velocity is

omega=(Deltatheta)/(Deltat)

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

omega=v/r

where,

v=11/4ms^(-1)

r=8/3m

So,

The angular velocity is

omega=(11/4)/(8/3)=1.03125rads^-1

The angular momentum is L=Iomega

where I is the moment of inertia

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

The mass is m=3 kg

So, I=3*(8/3)^2/2=10.67kgm^2

The angular momentum is

L=10.67*1.03125=11kgm^2s^-1