A solid disk, spinning counter-clockwise, has a mass of 12 kg and a radius of 6 m. If a point on the edge of the disk is moving at 8 m/s in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

Mar 4, 2017

$\omega = 1.33 r a {\mathrm{ds}}^{-} 1$

$p = 16 N m s$

Explanation:

Angular velocity is given by the equation

$\omega = \frac{v}{r} = \frac{8 m {s}^{-} 1}{6 m} = 1.33 r a {\mathrm{ds}}^{-} 1$

It is in the units radians per second, or $r a {\mathrm{ds}}^{-} 1$.

Angular momentum is the product of angular velocity and mass, much like linear momentum is the product of linear velocity and mass, so

$p = m \omega = 12 \times 1.33 = 16 N m s$