$A$ person is rotating on a rotating table with their arms held down. Suddenly,they spread their arms out. What happens to their angular momentum?

$A$ thin circular ring of mass $M$ and radius $r$ is rotating about its axis with a constant angular velocity $\omega$. Two objects,each of mass $m$,are attached gently to the opposite ends of a diameter of the ring. The ring will now rotate with an angular velocity:

Explain with illustration the pure translation and combination of translation and rotation motion of a rigid body.

$A$ hot solid sphere is rotating about a diameter at an angular velocity $\omega_0$. If it cools so that its radius reduces to $\frac{1}{\eta}$ of its original value,its angular velocity becomes .............

$A$ cockroach of mass $\frac{M}{2}$ starts moving with velocity $V$ on the circumference of a disc of mass $M$ and radius $R$. What will be the angular velocity of the disc?

Different minerals are being mined from within the earth and multi-storeyed complexes are being constructed. Due to this activity,theoretically: