A solid disk, spinning counter-clockwise, has a mass of 4 kg4kg and a radius of 3/2 m32m. If a point on the edge of the disk is moving at 6/7 m/s67ms in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Apr 9, 2016

The moment of inertia of the disk =I= 1/2xxmr^2=1/2xx4xx(3/2)^2=4.5kgm^2I=12×mr2=12×4×(32)2=4.5kgm2
Angular velocity omega=v/rω=vr, 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 mv=67msandr=1.5m
Angular velocity omega=v/r=6/7xx1/1.5=4/7rads^-1ω=vr=67×11.5=47rads1,
Angular momentum =Ixxomega=4.5xx4/7=18/7kgm^2s^-1=I×ω=4.5×47=187kgm2s1