Embibe Experts Solutions for Chapter: Rotational Mechanics, Exercise 2: BEGINNER'S BOX - 2

Two rings have their moments of inertia in the ratio $4:1$ and their diameters are in the ratio $4:1$. Find the ratio of their masses.

Two bodies of masses $1 \mathrm{kg}$ and $2 \mathrm{kg}$ are attached to the ends of a $2 \mathrm{m}$ long weightless rod. This system is rotating about an axis passing through the middle point of the rod and perpendicular to the length. Calculate the M.I. of the system.

If the moment of inertia of a disc about an axis tangential and parallel to its surface be $I$, then what will be the moment of inertia about an axis tangential but perpendicular to the surface?

A disc is recast into a thin hollow cylinder of the same radius. Which will have a larger moment of inertia? Explain.

Why spokes are fitted in a cycle wheel?

A circular disc $A$ of radius $r$ is made from an iron plate of thickness $t$ and another circular disc $B$ of radius $4r$ is made from an iron plate of thickness $\frac{t}{4}$. Find the relation between the moment of inertia $I_A$ and $I_B$.

A square plate of side $l$ has mass per unit area $\mu$. Find its moment of inertia about an axis passing through the centre and perpendicular to its plane.

Three masses $m_1, m_2$ and $m_3$ are located at the vertices of an equilateral triangle of side $a$. What is the moment of inertia of the system about an axis along the median passing through $m_1$?