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 $2 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2018-03-25T07:13:04

The angular momentum is $=7kgm^2s^-1$ and the angular velocity is $=0.29rads^-1$

The angular velocity is

$omega=(Deltatheta)/(Deltat)$

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

$omega=v/r$

where,

$v=2ms^(-1)$

$r=7m$

So,

The angular velocity is

$omega=(2)/(7)=0.29rads^-1$

The angular momentum is $L=Iomega$

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

The mass is $m= 1kg$

So, $I=1*(7)^2/2=24.5kgm^2$

The angular momentum is

$L=24.5*0.29=7kgm^2s^-1$

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 2 m/s2 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?