Applications of Newton's Laws of Motion

IMPORTANT

Applications of Newton's Laws of Motion: Overview

This topic covers concepts such as Free Body Diagram, Motion of Connected Bodies, and Motion on Inclined Plane.

Important Questions on Applications of Newton's Laws of Motion

MEDIUM
IMPORTANT

A block of mass m is placed on a smooth wedge of inclination   θ.  The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is acceleration due to gravity) will be

MEDIUM
IMPORTANT

The coefficient of static friction, μs, between block A of mass 2 kg and the table as shown in the figure is 0.2. What would be the maximum mass value of block B so that, the two blocks do not move? The string and the pulley are assumed to be smooth and massless g=10 ms2.

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EASY
IMPORTANT

A block has been placed on an inclined plane with the slope angle   θ,  block slides down the plane at constant speed. The coefficient of kinetic friction is equal to :

MEDIUM
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 magnitude and direction of the force of friction acting on A.

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MEDIUM
IMPORTANT

A light string passing over a smooth light pulley connects two blocks of masses m1 and m2 (vertically). If the acceleration of the system is g 8 , then the ratio of the masses is –

EASY
IMPORTANT

Two masses  m1=5 kg and  m2=4.8 kg tied to a string are hanging over a light frictionless pulley. What is the acceleration of the masses when left free to move? (g=9.8 m s2 )

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EASY
IMPORTANT

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads 49 N when the lift is stationary. If the lift moves downward with an acceleration of 5 m s2, the reading of the spring balance will be,

MEDIUM
IMPORTANT

A particle starts sliding down a frictionless inclined plane. If Sn is the distance travelled by it from time t=(n-1) sec to t=n sec, the ratio SnSn+1 is

HARD
IMPORTANT

A block of mass m, connected to a light string wrapped over a disc pulley of mass 2 m and radius 2r, is being pulled by a constant horizontal force F as shown. Tangential acceleration of a point distant r from the axis of pulley is (Assume that there is no slipping between the string and the pulley)

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EASY
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A block of mass m is placed on a smooth inclined plane of inclination θ with the horizontal. The inclined plane is accelerated horizontally so that the block does not slide down. What is the vertical force exerted by the inclined plane on the block?

HARD
IMPORTANT

Ratio of tensions T1 & T2 is:-

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MEDIUM
IMPORTANT

In the figure, at the free end of the light string, a force F is applied so as to keep the suspended mass of 18 kg at rest. Then what is the force exerted by the ceiling on the system ? (assume that the string segments are vertical and the pulleys are light and smooth) (g = 10 m/s2)
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HARD
IMPORTANT

In which of the following cases the magnitude of the acceleration of the block A will be maximum (Neglecting friction, the mass of pulley and string)

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Two blocks are placed at rest on a smooth fixed inclined plane. A force F acts on the block of mass m1 and is parallel to the inclined plane, as shown in the figure. Both the blocks move up the incline. Then,

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(iii) Find the normal reaction between the blocks of mass m1 and m2.

MEDIUM
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Find all the normal reactions NAGNAB and the accelerations of A and B (All surfaces are frictionless)

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MEDIUM
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A helicopter of mass 2000 kg rises with a vertical acceleration of 15 m s-2. The total mass of the crew and the passengers is 500 kg. Give the magnitude and direction of the action of the rotor of the helicopter on the surrounding air.

EASY
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A force of 100 N is applied on block A. The contact force between B & C is. mA=mC=50 kg&mB=25 kg

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EASY
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A monkey of mass 40 Kg climbs on a massless rope which can stand a maximum tension of 500 N. In which of the following cases will the rope breaks? (Take g=10 m s-2)

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MEDIUM
IMPORTANT

A ball is held at rest initially at position A by two light strings as shown in the figure. When the horizontal string is cut, the ball starts swinging as a pendulum with point B as its other extreme position. What is the ratio of the tension in the supporting string in position B to its value at A before the horizontal string was cut.
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HARD
IMPORTANT

Taking friction to be absent everywhere, the magnitude of tension in the string connecting block B and block C is?