Two Block Problems

IMPORTANT

Two Block Problems: Overview

This Topic covers sub-topics such as Condition for Relative Motion between Two Blocks, Motion of Two Blocks on Horizontal Plane, Motion of Two Blocks in Contact and, Motion of Two Blocks on Inclined Plane

Important Questions on Two Block Problems

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IMPORTANT

Block A of mass m and block B of mass 2m are placed on a fixed triangular wedge by means of a massless inextensible string and a frictionless pulley as shown in figure. The wedge is inclined at 45° to the horizontal on both sides. The coefficient of friction between block A and the wedge is 23 and that between block B and the wedge is 13. If the system of A and B is released from rest, find the acceleration of A & B.

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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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MEDIUM
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A body B lies on a smooth horizontal table and another body A is placed on B. The coefficient of friction between A and B is μ. What acceleration given to B will cause slipping to occur between A and B

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
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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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HARD
IMPORTANT

A body is moving down a long inclined plane of 1 in 2. The co-efficient of kinetic friction between the body and the plane varies as μ=0.49 x where x is the distance moved down the plane. The body will have its maximum velocity when it reaches

 

MEDIUM
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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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MEDIUM
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In figure, the coefficient of friction between the floor and the block B is 0.1. The coefficient of friction between the blocks B and A is 0.2. The mass of A is m2 and of B is m. What is the maximum horizontal force F can be applied to the block B so that two blocks move together?
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EASY
IMPORTANT

A block of mass 10 kg is placed on rough horizontal surface whose coefficient of friction is 0.5. If a horizontal force of 100 N is applied on it, then acceleration of the block will be
(Take g=10 m s-2)

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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EASY
IMPORTANT

A force F=5 N is applied on the lower block as shown in figure. The work done by lower block on upper block for a displacement of 6 m of the upper block with respect to ground is take, g=10 m s-2

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HARD
IMPORTANT

A block of mass m=2 kg is placed on a plank of mass M=10 kg, which is placed on a smooth horizontal plane, as shown in the figure. The coefficient of friction between the block and the plank is μ=13. If a horizontal force F is applied on the plank, then the maximum value of F for which the block and the plank move together is g=10 m/s2

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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
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Block 1 sits on top of block 2 . Both of them have a mass of 1 kg. The coefficients of friction between blocks 1 and 2 are μs=0.75 and μk=0.60. The table is frictionless. A force P2 is applied on block 1 to the left, and force P on block 2 to the right. Obtain the minimum value of P=Pmin such that both blocks move relative to each other and fill Pmin2 in OMR.

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MEDIUM
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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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