Rigid Body

IMPORTANT

Rigid Body: Overview

This topic covers concepts, such as, Motion of a Rigid Body, Translational Motion, Variable Angular Acceleration & Acceleration of Point in Pure Rotational Motion etc.

Important Questions on Rigid Body

MEDIUM
IMPORTANT

A string is wrapped over a uniform cylinder, as shown in diagram. When cylinder is released, string unwraps without any slipping and cylinder comes down. Which of the following is true?

Question Image

MEDIUM
IMPORTANT

A cylinder is moving along a horizontal surface without slipping with an angular velocity ω=1.0 rad/s. If the rod is leaning on the cylinder with one end hinged. Then which of the following statements is/are correct for the moment when angle α=60°?

Question Image

MEDIUM
IMPORTANT

A uniform rod of length 4 m and mass 22 kg revolves with constant angular velocity $\omega$ about a vertical axis through a smooth joint A at one extremity of the rod so that it describes a cone of semi vertical angle 53° as shown in the figure. choose the INCORRECT statement(s). g=10 m s-1

Question Image

MEDIUM
IMPORTANT

A cylinder P of radius rP is being rotated at a constant angular velocity ωPj^ with the help of a motor about its axis that is fixed. Another cylinder Q of radius rQ free to rotate about its axis that is also fixed is touched with the pressed on P making angle θ between their axes. Soon after the cylinders are pressed against each other, a steady state is reached and the cylinder Q acquires a constant angular velocity. What can you conclude when the steady state is reached?

Question Image

MEDIUM
IMPORTANT

A disc placed on a frictionless horizontal plank is rotating with a constant angular velocity ω about its central vertical axis. Now the plank is made to move with a constant acceleration α on a straight path. If you assume initial location of the centre of disc as origin, direction of motion of the plank in negative y-axis of the coordinate system attached with the plank, which of the following equations represent trajectroy of instantaneous centre of rotation of the disc.

HARD
IMPORTANT

A disc of mass m and radius R is placed over a plank of mass m. There is sufficient friction between disc and plank to prevent slipping and there is no friction between plank and ground. A horizontal force F is applied at the centre of the disc, then

Question Image

EASY
IMPORTANT

A sleeve A can slide freely along a smooth rod bent in the shape of a half-circle of radius R (Fig.). The system is set in rotation with a constant angular velocity ω about a vertical axis OO'. The angle corresponding to the equilibrium position of the sleeve is given by θ. Then

Question Image

MEDIUM
IMPORTANT

A hemispherical bowl of radius R=0.2 m is rotating about its own axis vertically with an angular frequency ω. A particle of mass 0.02 kg on the frictionless inner surface of the bowl is also rotating with the same frequency ω. The particle is at a height h from the bottom of the bowl. Which of the following statement(s) is/are true? (Take, the least count in the measurement of h is 10-3 m)

MEDIUM
IMPORTANT

A double star is a system of two stars rotating about their centre of mass only under their mutual gravitational attraction. Let the stars have masses m and 2 mand let their separation be l. Their time period of rotation about their centre of mass will be proportional to

MEDIUM
IMPORTANT

Rotation of the lever OA is controlled by the motion of the contacting circular disk whose centre is given a horizontal velocity v. Determine the expression of the angular velocity of the lever OA in terms of x.

Question Image 

EASY
IMPORTANT

A solid body rotates about a stationary axis so that its angular velocity depends upon the rotation angle θ as ω=ω0-kθ, where ω0 and θ are positive constants. At the moment t=0, the angle θ=0. Which of the following variations are correct?

EASY
IMPORTANT

The angular velocity ω and the angular acceleration α are plotted with time as shown. Which of the following options are incorrect?

Question Image 

HARD
IMPORTANT

Consider a bob of mass m and having charge q attached with a light string of length l and pivoted at point O. It is released at rest at 60° with vertical. There are two regions - Region-I (left of line PQ) has a uniform and constant magnetic field B directed inside plane of paper. Region-II (right of line PQ) has a constant and uniform electric field E directed vertically up as shown. Consider no effect of gravity in both the regions.

Question Image 

MEDIUM
IMPORTANT

A small object is placed on a smooth table at a distance r0 from a hole in the centre of table. An ideal inextensible chord is attached to the object through this hole. The object is set into motion with initial velocity of magnitude v0 at right angle to the chord and at the same time, the chord is pulled through the hole at uniform speed cm s-1. Initially object is at point A0,r0 and at any time t, it is at point Prcosθ,rsinθ. Neglect the dimension of object. Choose CORRECT option (s).

Question Image 

EASY
IMPORTANT

A uniform disc is performing pure rolling on a smooth horizontal stationary surface with constant angular velocity (V/R) and linear velocity of centre of mass V as shown is fig. find the correct statements at the given instant of time (Radius of the disc is R) (Assume A,B,C,D are on the circumference of the disc.)

Question Image 

HARD
IMPORTANT

A thin uniform bar lies on a frictionless surface and is free to move in any way on the surface. Its mass is 0.16 kg and length 3 metres. Two particles each of mass 0.08 kg are moving on the same surface and towards the bar in a direction perpendicular to the bar, one with a velocity 10 m s-1 and the other with 6 m s-1 as shown in Figure. The first particle strikes the bar at A and the other at the point B. The points A and B are at distance 0.5 m from centre of the bar. The particle strike the bar at the same instant of time and stick to the bar on collision. Calculate the loss of kinetic energy of the system in the above collision process.

Question Image 

HARD
IMPORTANT

A uniform solid cylinder of radius R=15 cm rolls over a horizontal plane passing in to an inclined plane forming an angle α=30° with the horizontal. Find the maximum value of the velocity v0 which still permits the cylinder to roll onto the inclined plane section without a jump. The sliding is assumed to be absent.

Question Image 

MEDIUM
IMPORTANT

Which one of the following motion include translational motion of the rigid body?

EASY
IMPORTANT

What do you mean by the translational motion of a rigid body?

EASY
IMPORTANT

A body under translational motion is rigid if: