A solid disk, spinning counter-clockwise, has a mass of $18 kg$ and a radius of $4 m$ . If a point on the edge of the disk is moving at $2/3 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2016-11-26T07:28:09

The angular momentum is $=24kgm^2s^(-1)$
The angular velocity is $=1/6 Hz$

The angular velocity is $v=r omega$

$v=$ velocity $=2/3ms^(-1)$

and $r=$ radius $=4m$

So, angular velocity, $omega=v/r=2/3*1/4=1/6 Hz$

The angular momentum is $L=I*omega$

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

where $m=$ the mass $=18 kg$

Therefore, $I=18*4*4/2=144 kg m^2$

So, the angular momentum is $L=144*1/6=24kgm^2s^(-1)$

A solid disk, spinning counter-clockwise, has a mass of 18 kg18 kg and a radius of 4 m4 m. If a point on the edge of the disk is moving at 2/3 m/s2/3 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?