A solid disk, spinning counter-clockwise, has a mass of 5 kg and a radius of 6 m. If a point on the edge of the disk is moving at 6 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Nov 30, 2017

The angular momentum is =2.5kgm^2s^-1. The angular velocity is =1rads^-1

Explanation:

The angular velocity is

omega=(Deltatheta)/(Deltat)

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

omega=v/r

where,

v=6ms^(-1)

r=6m

So,

The angular velocity is

omega=(6)/(6)=1rads^-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= 5kg

So, I=5*(1)^2/2=2.5kgm^2

The angular momentum is

L=2.5*1=2.5kgm^2s^-1