Question

A solid disk, spinning counter-clockwise, has a mass of `4 kg` and a radius of `3/2 m`. If a point on the edge of the disk is moving at `6/7 m/s` in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

Answer 1

The moment of inertia of the disk =`I= 1/2xxmr^2=1/2xx4xx(3/2)^2=4.5kgm^2`
Angular velocity `omega=v/r`, where v = linear velocity of the poit at the age of the disk and r= radius of the disk,
Here `v=6/7m/s and r =1.5 m`
Angular velocity `omega=v/r=6/7xx1/1.5=4/7rads^-1`,
Angular momentum `=Ixxomega=4.5xx4/7=18/7kgm^2s^-1`