1005 Angular Momentum

$\begin{aligned} \vec L = I \vec \omega \end{aligned}$

$\vec L$ - Angular momentum of a rigid body rotating around a symmetry axis.
$I$ - Moment of inertia of body.
$\vec \omega$ - Angular velocity vector of body.

Exercises

(10.41) Under some circumstances, a star can collapse into an extremely dense object made mostly of neutrons and called a neutron star. The density of a neutron star is roughly $10^{14}$ times as great as that of ordinary solid matter. Suppose we represent the star as a uniform, solid, rigid sphere, both before and after the collapse. The star's initial radius was $7.0 \times 10^5$ km (comparable to our sun); its final radius is $16$ km. If the original star rotated once in 30 days, find the angular speed of the neutron star.