A solid disk, spinning counter-clockwise, has a mass of $4 k g$ $4 kg$ and a radius of $\frac{1}{2} m$ $1/2 m$ . If a point on the edge of the disk is moving at $\frac{12}{5} \frac{m}{s}$ $12/5 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2017-12-19T07:47:29

The angular momentum is $= 2.4 k g m^{2} s^{- 1}$ $=2.4kgm^2s^-1$

The angular velocity is

$omega=(Deltatheta)/(Deltat)$

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

$omega=v/r$

where,

$v=12/5ms^(-1)$

$r=1/2m$

So,

The angular velocity is

$omega=(12/5)/(1/2)=4.8rads^-1$

The angular momentum is $L=Iomega$

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

The mass is $m=4 kg$

So, $I=4*(1/2)^2/2=0.5kgm^2$

The angular momentum is

$L=0.5*4.8=2.4kgm^2s^-1$

A solid disk, spinning counter-clockwise, has a mass of 4 kg4kg4 kg and a radius of 1/2 m12m1/2 m. If a point on the edge of the disk is moving at 12/5 m/s125ms12/5 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?