Two racing cars of masses ${\mathrm{m}}_1 \& {\mathrm{m}}_2$ are moving in circles of radii $r_1 \& r_2$ respectively. Their speeds are such that each makes a complete circle in the same duration of time $\mathrm{t}$ The ratio of the angular momentum of the first to the second car is:

A circular disc of radius $r$ is rolling without slipping on a horizontal surface. What is the ratio of the translational KE and rotational KE of disc?

Select the correct statement:

A ring of mass $10 \mathrm{kg}$ and radius of $1 \mathrm{m}$ is rotating at the rate of  $\frac{300}{\mathrm{\pi }} \mathrm{RPM}$  then:

The moment of inertia of a body about a given axis is $1.2 {\mathrm{kgm}}^2$. Initially the body is at rest. In order to produce a rotational kinetic energy of $1500 \mathrm{J}$, an angular acceleration of $25 \mathrm{rad} {\mathrm{s}}^{-2}$ must be applied about that axis for a duration of.

A boy comes and sits suddenly on a circular rotating table. What will remain conserved for the table-boy system?

If a person sitting on a rotating stool with his hands outstretched, suddenly pulls his arms inside then his: