Embibe Experts Solutions for Chapter: Rotational Mechanics, Exercise 1: Exercise 1

Torque per unit moment of inertia is equal to

A rod of weight $W$ is supported by two parallel knife edges $A$ and $B$ and is in equilibrium in a horizontal position. The knives are at a distance $d$ from each other. The centre of mass of the rod is at distance $x$ from $A$. The normal reaction on $A$ is

A light rope is wound around a hollow cylinder of mass $4 \mathrm{kg}$ and radius $40 \mathrm{cm}$. If the rope is pulled with a force of $40 \mathrm{N}$, its angular acceleration is______.

Essential characteristic of equilibrium is

When a torque acting upon a system is zero, then which of the following will be constant?

Angular momentum of the particle rotating with a central force is constant due to:

A horizontal disk of moment of inertia $4.25 \mathrm{kg} {\mathrm{m}}^2$ with respect to its axis of symmetry is spinning counter-clockwise at $15$ revolutions per second about its axis, as viewed from above. A second disk of moment of inertia $1.80 \mathrm{kg} {\mathrm{m}}^2$ with respect to its axis of symmetry is spinning clockwise at $25$ revolutions per second as viewed from above about the same axis and is dropped on top of the first disk. The two disks stick together and rotate as one about their axis of symmetry. The new angular velocity of the system as viewed from above is close to-

Assertion $\left(A\right) :$ If the ice on the polar caps of the earth melts, then length of the day will increase.

Reason $\left(R\right) :$ Moment of inertia of earth increases, as ice on polar caps melts.

The correct answer is