Moment of Inertia

IMPORTANT

Moment of Inertia: Overview

This topic explains the moment of inertia by considering rotation about a fixed axis. It also explains the radius of gyration with the help of equations and diagrams.

Important Questions on Moment of Inertia

MEDIUM
IMPORTANT

From a triangular lamina of side a and mass m , a small triangular Lamina made by joining mid-points of sides of triangular lamina is cut. If Moment of Inertia of complete Lamina about COM is Io and Moment of Inertia of remaining Lamina about centroid is xI016, then find the value of x.

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EASY
IMPORTANT

Four point masses (each of mass m) are arranged in the X-Y plane. The moment of inertia of this array of masses about Y-axis is 

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EASY
IMPORTANT

A solid sphere, a thin ring and a cylinder of same mass and radius, held at rest are released simultaneously to roll down on an inclined plane. Which one will reach the bottom first?

EASY
IMPORTANT

Point masses 1, 2, 3 and 4 kg are lying at the points (0, 0, 0), (2, 0, 0), (0, 3, 0) and (-2, -2, 0), respectively. The moment of inertia of this system about the x-axis will be,

EASY
IMPORTANT

Four similar point masses (each of mass m) are placed on the circumference of a disk of mass M and radius R. The moment of inertia of the system about the normal axis through the center O will be,

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EASY
IMPORTANT

On the marks of 20 cm and 70 cm of a light meter scale, two weights, 1 kg and 4 kg, respectively, are placed. The moment of inertia (in kg m2) about the vertical axis through the 100 cm mark will be,

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EASY
IMPORTANT

M.O.I. of a disc is minimum about an axis 

EASY
IMPORTANT

The moment of inertia of hollow cylinder having density ρ and height h is πρhr42.

EASY
IMPORTANT

Describe the term moment of inertia of hollow cylinder?

EASY
IMPORTANT

The moment of inertia of a hollow cylinder of mass M and inner radius R1 and outer radius R2 about its central axis is

EASY
IMPORTANT

A flywheel is used in an automobile engine due to its:

MEDIUM
IMPORTANT

Why fly wheels are used in vehicles?

EASY
IMPORTANT

The moment of inertia of a circular ring about an axis passing through its centre and perpendicular to its plane is 200 g cm2. If the radius of the ring is 5 cm, find the mass of the ring.

HARD
IMPORTANT

Fly wheel is an important part of an engine because:

EASY
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The moment of inertia of a rigid body depends on:

HARD
IMPORTANT

A uniform thin rod AB of length L and mass m is undergoing rotation about a fixed axis passing through end A and perpendicular to the rod, such that end A remains stationary as shown. The kinetic energy of section AP of the rod is equal to the kinetic energy of section BP of the rod at an instant. Then what is the value of ABAP3?

(AB and AP are lengths of respective parts of the rod)

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HARD
IMPORTANT

A solid cylinder is made of radius R and height 3R having mass density ρ . Now two half spheres of radius R are removed from both ends. The moment of inertia of remaining portion about axis ZZ' can be calculated as 296KπR5ρ . Find K.
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EASY
IMPORTANT

Two identical water bottles one empty and the other filled with water are allowed to roll down an inclined plane. Which one of them reaches the bottom first? Explain your answer.