A solid disk, spinning counter-clockwise, has a mass of $1 kg$ and a radius of $7 m$ . If a point on the edge of the disk is moving at $3 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2017-03-06T13:22:09

The angular momentum is $=66kgm^2s^-1$
The angular velocity is $=2.69rads^-1$

The angular velocity is

$omega=v/r$

where,

$v=3ms^(-1)$

$r=7m$

So,

$omega=(3)/(7)*2pi=6/7pi=2.69rads^-1$

The angular momentum is $L=Iomega$

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

So, $I=1*(7)^2/2=49/2kgm^2$

The angular momentum is

$L=2.69*49/2=66kgm^2s^-1$

A solid disk, spinning counter-clockwise, has a mass of 1 kg1 kg and a radius of 7 m7 m. If a point on the edge of the disk is moving at 3 m/s3 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?