EASY
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Starting from rest, a car moves with a constant acceleration, and comes to a momentary stop with the same constant deceleration. Subsequently, it reverses its motion and returns to its original position in a similar manner. Which one of the following graphs of momentum (p) versus time (t) best describes the motion of the car?

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Important Questions on Laws of Motion

EASY

A time varying force acts on a ball of mass 100 g for 2 ms. The force versus time curve is shown below. If the initial speed of the ball is 10 m s-1, then the speed of ball after 2 ms is

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MEDIUM
A carrom coin of radius 1.5cm and mass 5g strikes the side of the board at an angle 30° with respect to the normal. The coin stays in contact with the side for 10-3s and rebounds at an angle of 45° with respect to the normal. The initial speed of the coin is 1ms-1 and its final speed is 0.7ms-1. The average impulsive force on the coin in the normal direction is about
EASY
In two different experiments, an object of mass 5 kg moving with a speed of 25 ms-1 hits two different walls and comes to rest within
(i) 3 second, (ii) 5 seconds, respectively.
Choose the correct option out of the following :
MEDIUM
A particle having a mass 0.5 kg is projected under gravity with a speed of 98 m sec-1 at an angle of 60°.  The magnitude of the change in momentum (in N sec) of the particle after 10 seconds is g=9.8 m s-2
MEDIUM

Two billiard balls of equal mass 30 g strike a rigid wall with same speed of 108 km h-1 (as shown) but at different angles. If the balls get reflected with the same speed, then the ratio of the magnitude of impulses imparted to ball a and ball b by the wall along X direction is:

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EASY

A rigid ball of mass,  m strikes a rigid wall at 60o and gets reflected without any loss of speed as shown in the figure below. The value of impulse imparted by the wall on the ball will be
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MEDIUM

A block of mass M at rest on the floor is attached to a ball of mass M2 via a light inextensible string of length L which passes over a light small frictionless pulley. The pulley is at a height of 0.6 L from the floor. The ball is raised to a height of L6  and released (see figure). The speed of the block at the instant the string gets taut (not slack) will be

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EASY
Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity g is:
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MEDIUM
A bullet of 4 g mass is fired from a gun of mass 4 kg. If the bullet moves with the muzzle speed of 50 ms1, the impulse imparted to the gun and velocity of recoil of gun are 
MEDIUM
A ball of mass 0.15 kg is dropped from a height 10 m strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is g=10 m s-2 nearly :
EASY
A batsman hits back a ball of mass 0.4 kg straight in the direction of the bowler without changing its initial speed of 15 m s-1. The impulse imparted to the ball is _____ N s.
EASY

The correct dimensional formula for impulse is given by

EASY
On a smooth plane surface (figure) two block A and B are accelerated rightwards by applying a force 15 N on A. If mass of B is twice that of A, the force on B is

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MEDIUM

Figures (a), (b), (c) and (d) show variation of force with time.

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The impulse is highest in figure.

EASY
A machine gun has a mass 5 kg. It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of 400 m s-1. What force is required to keep the gun in position?
EASY
The time taken by a force of 2 N to produce a change of momentum of 0.4 kg m s-1 in a
EASY

A block A of mass 100 kg rests on another block B of mass 200 kg and is tied to a wall as shown in the figure. The coefficient of friction between A and B is 0.2 and that between B and ground is 0.3. The minimum force required to move the block B is g=10 m s-2

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EASY

A ball of mass 3 kg, moving with a speed of 100 m s-1, strikes a wall at an angle 60° (as shown in figure). The ball rebounds at the same speed and remains in contact with the wall for 0.2 s; the force exerted by the ball on the wall is:

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EASY

Figure represents the position-time graph of a body of mass 4 kg. Impulse kg m s-1 imparted to the body at t=0 is

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MEDIUM

The force F' acting on a particle of mass m' is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is:
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