A solid disk, spinning counter-clockwise, has a mass of $12 kg$ and a radius of $5/2 m$ . If a point on the edge of the disk is moving at $4/3 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2017-07-22T06:47:32

The angular momentum is $=20kgm^2s^-1$ and the angular velocity is $=0.053rads^-1$

The angular velocity is

$omega=(Deltatheta)/(Deltat)$

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

$omega=v/r$

where,

$v=4/3ms^(-1)$

$r=5/2m$

So,

$omega=(4/3)/(5/2)=8/15=0.053rads^-1$

The angular momentum is $L=Iomega$

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

So, $I=12*(5/2)^2/2=75/2kgm^2$

The angular momentum is

$L=75/2*8/15=20kgm^2s^-1$

A solid disk, spinning counter-clockwise, has a mass of 12 kg12 kg and a radius of 5/2 m5/2 m. If a point on the edge of the disk is moving at 4/3 m/s4/3 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?