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A particle moves a distance x in time t according to equation x=t+5-1. The acceleration of particle is proportional to

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Important Questions on Newton's Laws of Motion

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A bomb at rest explodes into 3 parts of same mass. The momentum of two parts is -3pi^ and 2pj^ respectively. The magnitude of momentum of the third part is
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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
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A balloon has a mass of 10 gram in air. The air escapes from the balloon at a uniform rate with a velocity of 5 cm s-1 and the balloon shrinks completely in 2.5 s. The average force acting on the balloon will be
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
A body of mass 4m is lying in x - y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass m move perpendicular to each other with equal speeds υ. The total kinetic energy generated due to explosion is:
MEDIUM
A spaceship in space sweeps stationary interplanetary dust. As a result, its mass increases at a rate dMtdt=bv2t, where vt is its instantaneous velocity. The instantaneous acceleration of the satellite is:
MEDIUM
A stationary body explodes into two parts of masses M1 and M2. They move in opposite directions with velocities v1 and v2. The ratio of their kinetic energies is
HARD

A solid sphere of mass 1 kg and radius 1 m rolls without slipping on a fixed inclined plane with an angle of inclination θ=30° from the horizontal. Two forces of magnitude 1 N each, parallel to the incline, act on the sphere, both at distance r=0.5 m from the center of the sphere, as shown in the figure. The acceleration of the sphere down the plane is m s-2. (Take g=10 m s-2)

If the numerical value has more than two decimal places, truncate/round-off the value to TWO decimal places.

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HARD
A man (mass =50 kg ) and his son (mass =20 kg ) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of 0.70 m s-1 with respect to the man. The speed of the man with respect to the surface is:
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Two particles which are initially at rest move towards each other under the action of their mutual attraction. If their speeds are v and 2v at any instant, then the speed of center of mass of the system is,
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A 5000 kg rocket is set for vertical firing. The exhaust speed is  800ms1.  To give an initial upward acceleration of 20 m s-2, the amount of gas ejected per second to supply the needed thrust will be:  g=10ms2
HARD

Two inclined planes are placed as shown in figure.
A block is projected from the Point A of inclined plane AB along its surface with a velocity just sufficient to carry it to the top Point B at a height 10 m. After reaching the Point B the block slides down on inclined plane BC. Time it takes to reach to the point C from point A is t2+1s. The value of t is _____ (use g=10 m s-2)

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MEDIUM
A small block slides without friction down an inclined plane starting from rest. Let Sn be the distance travelled from t=n-1 to t=n, then SnSn+1 is 
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A block of mass m lies on the wedge of mass M, which lies on the fixed horizontal surface. The wedge is free to move on the horizontal surface. A horizontal force of magnitude F is applied on the block as shown, neglecting friction at all surfaces, the value of force F such that block has no relative motion with respect to the wedge will be (Where g is the acceleration due to gravity)

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EASY

A container of liquid is released from the rest, on a smooth inclined plane as shown in the figure. Length of at the inclined plane is sufficient, and assume liquid finally equilibrium. Finally, the liquid surface makes an angle horizontal.......

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EASY
A block is placed on a rough horizontal plane. A time dependent horizontal force F=kt acts on the block. Here k is a positive constant. Acceleration time graph of the block is
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Two blocks of equal masses m are released from the top of a smooth fixed wedge as shown in the figure. The acceleration of the centre of mass of the two blocks is
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A system is accelerated upward with an acceleration 5 g. The apparent weight of a body of mass m in the system is -
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In the figure shown a ring of mass M and a block of mass m are in equilibrium. The string is light and pulley P dose not offer any friction and coefficient of friction between pole and M is μ. The frictional force offered by the pole on M is

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MEDIUM

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 slab is 0.60 while the kinetic coefficient is 0.40. The 10 kg block is acted upon by a horizontal force of 100 N. If g=9.8 m s-2, the resulting acceleration of the slab will be-

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