A solid disk, spinning counter-clockwise, has a mass of #5 kg# and a radius of #4 m#. If a point on the edge of the disk is moving at a rate of #2 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
May 5, 2017

Answer:

The angular momentum is #=20kgm^2s^-1#
The angular velocity is #=0.5rads-1#

Explanation:

The angular velocity is

#omega=(Deltatheta)/(Deltat)#

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

#omega=v/r#

where,

#v=2ms^(-1)#

#r=4m#

So,

#omega=(2)/(4)=0.5rads^-1#

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=5*(4)^2/2=40kgm^2#

The angular momentum is

#L=40*0.5=20kgm^2s^-1#