Two-Block Problems

IMPORTANT

Two-Block Problems: Overview

This topic covers concepts such as Motion of Two Blocks on Inclined Plane, Motion of Two Blocks on Horizontal Plane, Condition for Relative Motion between Two Blocks, and Motion of Two Blocks in Contact.

Important Questions on Two-Block Problems

HARD
IMPORTANT

Two blocks connected by a massless string slide down an inclined plane having an angle of inclination of   37°.  The masses of the two blocks are   M 1 =4kg  and   M 2 =2kg  respectively and the coefficients of friction of   M 1 and   M 2 with the inclined plane are 0.75 and 0.25 respectively. Assuming the string to the taut, find the tension in the string.   ( sin37°=0.6,cos37°=0.8 )

HARD
IMPORTANT

Two blocks connected by a massless string slide down an inclined plane having an angle of inclination of 37°. The masses of the two blocks are M1=4 kg and M2=2 kg respectively and the coefficients of friction of M1 and M2 with the inclined plane are 0.75 and 0.25 respectively. Assuming the string to be taut, find the common acceleration of two masses. sin37°=0.6, cos37°=0.8

EASY
IMPORTANT

In the arrangement coefficient of friction between the two blocks is μ=13. The force of friction acting between the two blocks is: g=10 m s-2

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EASY
IMPORTANT

A man sitting in a train in motion is facing the engine. He tosses a coin up, the coin falls behind him. The train is moving

MEDIUM
IMPORTANT

A single horizontal force F is applied to a block of mass M1, which is in contact with another block of mass M2(Given figure). If the surfaces are frictionless, the force between the blocks is

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MEDIUM
IMPORTANT

Two blocks of masses M=5 kg and m=3 kg are placed on a horizontal surface as shown in fig. The coefficient of friction between the blocks is 0.5 and that between the block M and the horizontal surface is 0.7. What is the maximum horizontal force F that can be applied to block M so that the two blocks move without slipping ? Take g=10 m/s2

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HARD
IMPORTANT

Blocks A and B are arranged as shown in the figure. The pulley is frictionless. The mass of A is 10 kg. The coefficient of friction between the block A and the horizontal surface is 0.20. The minimum mass of B, to start the motion, will be

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MEDIUM
IMPORTANT

In the arrangement shown in the figure, if the blocks of masses m and 2 m are released from the state of rest, tension in the string is (μ= coefficient of friction, string is massless and inextensible, pulley is frictionless)

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EASY
IMPORTANT

In the situation shown, the reading of the spring balance is g=10 m s-2

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MEDIUM
IMPORTANT

If F force is applied to 10 kg block as shown in diagram then maximum value of F so that there is no relative motion between the blocks.

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MEDIUM
IMPORTANT

Calculate the accelerations of the blocks A and B:-

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MEDIUM
IMPORTANT

A force of 0.5 N is applied on the upper block as shown in figure. The coefficient of static friction between the two blocks is 0.1 and that between the lower block and the surface is zero. The work done by the lower block on the upper block for a displacement of 3 m of the upper block is :-

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EASY
IMPORTANT

In friction is present between A & B only and F> limiting friction between A & B. Find acceleration of A & B.

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MEDIUM
IMPORTANT

In the given arrangement of a doubly inclined plane two blocks of masses M and m are placed. The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of friction between the surface of the plane and the blocks is 0.25. The value of m, for which M=10 kg will move down with an acceleration of 2 m s-2, is : (take g=10 m s-2 and tan 37°=34)

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HARD
IMPORTANT

A block of mass m sits on the top of a block of mass 2m which sits on a table. The coefficient of kinetic friction between all surface is μ = 1 . A massless string is connected to each mass and wraps halfway around a massless pulley, as shown. Assume that you pull on the pulley with a force of 6mg. The acceleration of your hand is -
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MEDIUM
IMPORTANT

Two blocks of masses m and 2m are placed one over the other as shown in the figure. The coefficient of friction between m and 2m is μ and between 2m and ground is μ3. If a horizontal force F is applied on the upper block and T is the tension developed in the string, then choose the incorrect alternative.
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EASY
IMPORTANT

In the figure, mA=2 kg and mB=4 kg. For what minimum value of force FA starts slipping over B g=10 m s-2

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MEDIUM
IMPORTANT

Two blocks A and B are placed one over the other on a smooth horizontal surface. The maximum horizontal force that can be applied on the lower block A, so that A and B move without separation is 49 N. The coefficient of friction between A and B is ( take g=9.8 m s-2 )

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EASY
IMPORTANT

Two blocks masses 1 kg and 2 kg rest on a smooth horizontal table. When the 2 kg block is pulled by a certain force F, the tension T in the string is 1.5 N. The value of F is


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MEDIUM
IMPORTANT

A 40 kg slab rests on a frictionless floor. A 10 kg block rests on top of the slab. The static coefficient of friction between the block and the slab is 0.60 while the kinetic coefficient of friction is 0.40. The 10 kg block is acted upon by a horizontal force of 100 N. If g=9.8 ms-2, the resulting acceleration of the slab will be


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