A solid disk, spinning counter-clockwise, has a mass of $7 kg$ and a radius of $5/2 m$ . If a point on the edge of the disk is moving at $4/3 m/s$ in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

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Answer 1 · 2016-12-14T14:19:58

The angular momentum is $=146.6kgms^(-1)$

The angular velocity is $=3.35rads^(-1)$

The angular velocity is $omega=v/r$

$v=4/3ms^(-1)$

$r=5/2m$

$omega=4/3*2/5=8/15Hz=16/15pi rads^(-1)=3.35rads^(-1)$

The angulur momentum is $L=Iomega$

The moment of inertia of a solid disc is $=mr^2/2$

$I=7*(5/2)^2=7*25/4kgm^2$

Therefore,

$L=16/15*pi*175/4 kgm^2s^(-1)=146.6kgms^(-1)$

A solid disk, spinning counter-clockwise, has a mass of 7 kg7 kg and a radius of 5/2 m5/2 m. If a point on the edge of the disk is moving at 4/3 m/s4/3 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?