Center of Mass

IMPORTANT

Center of Mass: Overview

This topic describes the centre of mass of a system and its significance. It also contains mathematical expressions to prove the centre of mass with the example of rod and lamina.

Important Questions on Center of Mass

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For a bangle, the centre of mass lie outside the body.

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For which of the following does the centre of mass lie outside the body ?

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The centre of mass of solid hemisphere of radius 8 cm is x from the centre of the flat surface. Then value of x in cm is _________ .

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Give an example to show that the following statement is false. 'Any two forces acting on a body can be combined into single force that would have same effect'.

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For the given uniform square lamina ABCD whose centre is O, pick incorrect statement :-

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The y coordinate of centre of mass of a thin and uniform semicircular ring of radius r shown in figure is

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Centre of mass of a uniform ring is at the _____ of the ring.
(Choose from: circumference/centre)

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Consider a two-particle system with particles having masses m1 and m2. If the first particle is pushed towards the centre of mass through a distance d, by what distance should the second particle be moved, so as to keep the centre of mass at the same position?

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Which of the following points is the likely position of the centre of mass of the system shown in figure?
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Two particles each of mass 1 g are placed at a distance of 1 m and 3 m respectively from the origin along X-axis. The centre of the mass of the system of the particles is

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Two particles each of mass 1 g are placed at a distance of 1 m and 3 m respectively from the origin along x-axis. The centre of the mass of the system of the particles is

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Centre of mass of a uniform ring is at the _____ of the ring.

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Two particles A and B, initially at rest, move towards each other under a mutual force of attraction. At the instant when the speed of A is v and the speed of B is 2v, the speed of the center of mass of the system is:

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A projectile is launched from the origin with speed v at an angle θ from the horizon. At the highest point in the trajectory, the projectile breaks into two pieces, A and B of masses m and 2m respectively. Immediately after the breakup, piece A is at rest relative to the ground. Neglect air resistance. Which of the following sentences most accurately describes what happens next? 
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In a HCl molecule, the separation between the nuclei of the two atoms is about 1.27 Å 1 Å=10-10 m. Given that a chlorine atom is about 35.5 times as massive as a hydrogen atom and nearly all the mass of an atom is concentrated in its nucleus, the position of centre of mass of the molecule is

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Center of mass of three particles of masses 1 kg, 2 kg and 3 kg lies at the point (1, 2, 3) and center of mass of another system of particles 3 kg and 2 kg lies at the point (-1, 3,-2). The point at which a particle of mass 5 kg be placed, so that the center of mass of first system coincides with centre of mass of whole system is:

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The center of mass of a system of two particles of masses m1 and m2 is at a distance d1 from m1 and at a distance d2 from mass m2, such that:

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The x-y coordinates of the center of mass of a uniform L shaped lamina of mass 3 kg is:
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Three particles of masses 1 kg, 32 kg and 2 kg are located at the vertices of an equilateral triangle (see figure below). The coordinates of centre of mass of this system is located at:

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Find the coordinates of the centre of mass of the non-uniform circular ring of radius R given below. Take the origin to be at the centre of the circle. Let θ be the angle that the radius vector through any element or the ring makes with the x-axis. The density of the circular ring as a function of θ is given as ρ=a|sinθ| (where a is a constant)

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