A solid disk, spinning counter-clockwise, has a mass of $4 kg$ and a radius of $3/4 m$ . If a point on the edge of the disk is moving at $5/9 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2017-02-10T07:27:29

The angular momentum is $=5.24kgms^(-1)$
The angular velocity is $=4.65rads^-1$

The angular velocity is

$omega=v/r$

where,

$v=5/9ms^(-1)$

$r=3/4m$

So,

$omega=(5/9)/(3/4)*2pi=(40/27pi)=4.65rads^-1$

The angular momentum is $L=Iomega$

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

So, $I=4*(3/4)^2/2=9/8kgm^2$

$L=4.65*9/8=5.24kgms^(-1)$

A solid disk, spinning counter-clockwise, has a mass of 4 kg4 kg and a radius of 3/4 m3/4 m. If a point on the edge of the disk is moving at 5/9 m/s5/9 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?