
question_answer1) The action and reaction forces referred to in Newton's third law of motion
A) Must act on same body
B) Must act on different bodies need not be equal in magnitude but must have
C) The same line of action
D) Must be equal in magnitude but need not have the same line of action
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question_answer2) A longjumper runs before jumping to
A) Cover greater distance
B) Maintain momentum conservation
C) Gain energy by running
D) Gain momentum
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question_answer3) If a rock is brought from the surface of the moon, then
A) Its mass will change
B) Its weight will change, but not mass
C) Both mass and weight will change
D) Its mass and weight will remain the same
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question_answer4) A false balance has equal arms. An object weights \[{{w}_{1}}\] when placed in one pan and \[{{w}_{2}}\] when placed in the other pan. Then weight w of the object is
A) \[\sqrt{{{w}_{1}}{{w}_{2}}}\]
B) \[\frac{{{w}_{1}}+{{w}_{2}}}{2}\]
C) \[\left( \frac{{{w}_{1}}^{2}+{{w}_{2}}^{2}}{2} \right)\]
D) \[\sqrt{{{w}_{1}}^{2}+{{w}^{2}}_{2}}\]
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question_answer5) The force acting on a mass of 1 g due to the gravitational pull on the earth is called 1 g wt. One g wt equals
A) 1 N
B) 9.8 N
C) 980 dyne
D) None of these
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question_answer6) Weight of a body would not be zero
A) At the centre of the earth
B) During a free fall
C) In interplanetary space
D) On a frictionless surface
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question_answer7) Which of the following physical quantities has no unit?
A) Relative density
B) Density
C) Pressure
D) Thrust
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question_answer8) A particle of mass moving eastward with a speed v collides with another particle of the same mass moving northwards with the same speed u. The two particles coalesce on collision. The new particle of mass 2 m will move in the northeasterly direction with a velocity
A) \[\frac{\sqrt{\upsilon }}{\sqrt{2}}\]
B) \[\frac{\upsilon }{2}\]
C) \[\frac{\upsilon }{\sqrt{2}}\]
D) None of these
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question_answer9) Two bodies of masses 0.03 kg, and 0.04 kg, are tied to the ends of a massless string. This string passes over the frictionless pulley. The tension in the string is
A) 0.336 N
B) 0.294 N
C) 683N
D) 0.392 N
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question_answer10) In the above problem, acceleration of the system is
A) \[\text{4}.\text{9 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{2}.\text{94 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{1}.\text{4 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}}\]
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question_answer11) An iron ball and a wooden ball of the same radius are released from a height H in vacuum. The times taken by both of them of reach the ground are
A) Roughly equal
B) Unequal
C) Exactly equal
D) In the inverse ratio of their diameters
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question_answer12) A man is standing on a boat in still water If he walks towards the shore the boat will
A) Move away from the shore
B) Remain stationary
C) Move towards the shore
D) Sink
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question_answer13) During a planned man oeuvre in a space flight, a freefloating astronaut A pushes another Free floating astronaut B, the mass of A being greater than that of B. Then, the magnitude of the force exerted by astronaut A on astronaut B is
A) Equal to zero
B) Equal to the force exerted by B on A
C) Greater than the force exerted by B on A
D) Less than the force exerted by B on A
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question_answer14) In the above problem, during a push
A) Acceleration of A is greater than that of B
B) Acceleration of A is less than that of B
C) Neither is accelerated
D) Their accelerations are equal in magnitude but opposite in direction
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question_answer15) A body of mass 300 gm is at rest. What force in Newton will you have to apply to move it through 200 cm in 10 sec.?
A) Zero
B) 12 Newton
C) 1.2 Newton
D) 0.12 Newton
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question_answer16) A body of mass 2 kg is acted upon by two forces each of magnitude 1 Newton, making an angle of \[60{}^\circ \] with each other. The net acceleration of the body (in\[\text{m}/{{\text{s}}^{\text{2}}}\]) is
A) \[\frac{\sqrt{2}}{3}\]
B) \[\frac{\sqrt{3}}{2}\]
C) 0.5
D) 1.0
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question_answer17) A parachutist of weight w strikes the ground and comes to rest with an upward acceleration of magnitude 3 g. Force exerted on him by the ground during landing is
A) \[2w\]
B) 3 \[w\]
C) 4 \[w\]
D) 5 \[w\]
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question_answer18) A boat of mass 3000 kg, initially at rest is pulled by a force of \[\text{1}.\text{8 x 1}{{0}^{\text{4}}}\] Newton through a distance of 3 m. Assuming that the resistance due to water is negligible, velocity of boat is
A) 6 m/s
B) 8 m/s
C) 9 m/s
D) 11 m/s
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question_answer19) A bullet of mass A and velocity B is fired into a block of wood of mass C. If loss of any mass and friction be neglected, then velocity of the system must be
A) \[\frac{AB}{A+C}\]
B) \[\frac{A+C}{B+C}\]
C) \[\frac{AC}{B+C}\]
D) \[\frac{A+B}{AC}\]
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question_answer20) A dish of mass 10 gm is kept horizontally in air by firing bullets of mass 5 g each at the rate of 10 per sec. If the bullets rebound with the same speed, what is the velocity with which the bullets are fired?
A) 49 cm/sec
B) 147 cm/sec
C) 98 cm/sec
D) 196 cm/sec
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question_answer21) Three equal weights of mass 2 kg each are hanging on a string passing over a fixed pulley as shown in the fig. What is the tension in the string connecting the weights B and C?
A) Zero
B) 13 N
C) 3.3 M
D) 19.6 N
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question_answer22) In the arrangement shown in figure below, the ends P and Q of an stretchable string move downwards with uniform speed u. Pulleys A and B are fixed. Mass M moves upwards with a speed
A) \[2u\cos \theta \]
B) \[u\cos \theta \]
C) \[\frac{2u}{\cos \theta }\]
D) \[\frac{u}{\cos \theta }\]
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question_answer23) A body of mass 1 kg initially at rest, explodes and breaks into three fragments of masses in the ratio 1:1:3. The two pieces of equal masses fly off perpendicular to each other with a speed of 30 m/s each. What is the velocity of the heavier fragment?
A) 10 m/s
B) 20 m/s
C) \[10\sqrt{2}\,\,m/s\]
D) \[20\sqrt{2}\,\,m/s\]
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question_answer24) Two bodies with masses \[{{m}_{1}}\] and \[{{m}_{2}}\] \[({{m}_{1}}>{{m}_{2}})\] are joined by a string passing over a fixed pulley. The centres of gravity of the two bodies are initially at the same height. Assume mass of the pulley and weight of the thread negligible. Then the downwards acceleration of \[{{m}_{1}}\] is
A) \[\left( \frac{{{m}_{1}}{{m}_{2}}}{{{m}_{1}}+{{m}_{2}}} \right)g\]
B) \[{{\left( \frac{{{m}_{1}}{{m}_{2}}}{{{m}_{1}}+{{m}_{2}}} \right)}^{2}}g\]
C) \[\frac{{{m}_{2}}g}{{{m}_{1}}+{{m}_{2}}}\]
D) \[\frac{{{m}_{1}}g}{{{m}_{1}}+{{m}_{2}}}\]
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question_answer25) In the above question, the time after which the centres of gravity of the two bodies will have a separation h, is
A) \[\sqrt{\frac{h}{g}{{\left( \frac{{{m}_{2}}+{{m}_{2}}}{{{m}_{2}}{{m}_{2}}} \right)}^{2}}}\]
B) \[\sqrt{\frac{h}{g}\left( \frac{{{m}_{1}}+{{m}_{2}}}{{{m}_{1}}{{m}_{2}}} \right)}\]
C) \[\sqrt{\frac{2h}{g}\left( \frac{{{m}_{2}}+{{m}_{2}}}{{{m}_{2}}{{m}_{2}}} \right)}\]
D) \[\sqrt{\frac{h}{2g}\left( \frac{{{m}_{2}}+{{m}_{2}}}{{{m}_{2}}{{m}_{2}}} \right)}\]
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question_answer26) A number of discs, each of momentum M kg m/s are striking a wall at the rate of n discs per minute. The force associated with these discs, in new tons, would be
A) \[\frac{Mn}{60}\]
B) \[60\,mn\]
C) \[\frac{M}{60\,n}\]
D) \[\frac{n}{60M}\]
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question_answer27) If action and reaction were to act on the same body, then
A) Resultant would be zero
B) Body would not move at all
C) Both [a] and [b]
D) None of these
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question_answer28) 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 is 0.40. The 10 kg block is acted upon by horizontal force 100N. If\[\text{g }=\text{ 9}.\text{8 m}/{{\text{s}}^{\text{2}}}\], then resulting acceleration of the slab will be
A) \[0.\text{98 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{1}.\text{47 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{1}.\text{52 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{6}.\text{1 m}/{{\text{s}}^{\text{2}}}\]
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question_answer29) A rear side of a truck is open and a box of mass 20 kg is placed on the truck 4 metres away from the open end. \[\mu =0.15\] and\[\text{g }=\text{ 1}0\text{ m}/{{\text{s}}^{\text{2}}}\]. The truck starts from rest with an acceleration of \[\text{2 m}/{{\text{s}}^{\text{2}}}\]on a straight road. The box will fall off the truck when it is at a distance from the starting point equal to
A) 4 metres
B) 8 metres
C) 16 metres
D) 32 metres
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question_answer30) A shell is fired from a cannon with a velocity u at an angle \[\theta \] with the horizontal direction. At the highest point in its path, it explodes into two pieces of equal mass. One of the pieces retraces its path of the cannon. Speed of the other piece immediately after the explosion is
A) \[3\,v\,\cos \,\theta \]
B) \[2\,v\,\cos \,\theta \]
C) \[\frac{3}{2}\,v\,\cos \,\theta \]
D) \[\frac{\sqrt{3}}{2}\,v\,\cos \,\theta \]
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question_answer31) A stone is tied to the middle of a string and suspended from one end as shown in the figure. Here S is the stone and 0 is the pint of suspension. (i) If you give a sharp jerk at P, the string will break
A) Below the stone
B) At the point P itself
C) From above the stone
D) Nothing can be decided
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question_answer32) A stone is tied to the middle of a string and suspended from one end as shown in the figure. Here S is the stone and 0 is the pint of suspension. (ii) If we increase the pull at P gradually, the string will break
A) Below the stone
B) At the point P itself
C) Above the stone
D) Nothing can be decided
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question_answer33) The combined effect of mass and velocity is taken into account by a physical quantity called
A) Torque
B) Moment of force
C) Momentm
D) Moment of momentum
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question_answer34) Momentum is a measure of
A) Weight
B) Mass
C) Quantity of motion
D) Velocity
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question_answer35) Momentum has the same units as that of
A) Impulse
B) Torque
C) Moment of momentum
D) Couple
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question_answer36) A ball moving with a velocity u strikes a wall moving toward the ball with a velocity u. An elastic impact lasts for t sec. Then the mean elastic force acting on the ball is
A) \[\frac{2m\upsilon }{t}\]
B) \[\frac{2m(\upsilon +u)}{t}\]
C) \[\frac{2m(\upsilon +2u)}{t}\]
D) \[\frac{m(\upsilon +2u)}{t}\]
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question_answer37) When effort is applied parallel to an inclined frictionless plane making an angle \[\theta \] with the horizontal, then mechanical advantage of the system is
A)
B) \[\tan \theta \]
C) \[\cot \theta \]
D) \[\text{cosec }\theta \]
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question_answer38) A block is released from rest at the top of a frictionless inclined plane 16 m long. It reaches the bottom 4 sec later. A second block is projected up the plane from the bottom at the instant the block is released in such a way that it returns to the bottom simultaneously with first block. The acceleration of each block on the incline is
A) \[\text{1 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{2 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{4 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}}\]
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question_answer39) In a tugofwar between the teams A and B, the rope breakes at a point which is nearer to A. Then
A) A has applied more force
B) B has applied more force
C) A and B both have applied same force
D) None has applied any force
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question_answer40) A rocket works on the which law of motion?
A) First law
B) Second law
C) Third law
D) None of these
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question_answer41) The total mass of an elevator, with a 80 kg man in it, is 1000 kg. This elevator moving upward with a speed of 8 m/s is brought to rest over a distance 16 m. Then tension T in the cable supporting elevator is
A) 3200 N
B) 5400 N
C) 6500 N
D) 7800 N
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question_answer42) A body moves along circular path of radius 10 m and the coefficient of friction is 0.5. What should be its angular velocity in rad/sec if it is not to slip from the surface?\[\left( \text{g }=\text{ 9}.\text{8 m}/{{\text{s}}^{\text{2}}} \right)\]
A) 0.1
B) 0.7
C) 5
D) 10
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question_answer43) An insect is crawling up a fixed hemispherical bowl of radius R. If the coefficient of friction is 1/3, then the height upto which insect can crawl is
A) 2 % of R
B) 3 % of R
C) 4 % of R
D) 5 % of R
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question_answer44) It is difficult to walk on ice because of
A) Absence of friction
B) absence of inertia
C) More inertia
D) more friction
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question_answer45) Newton's which law which defines force?
A) First law
B) Second law
C) Third law
D) None of these
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question_answer46) Internal force
A) Are always balanced
B) Are never balanced
C) May or may not be balanced
D) None of these
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question_answer47) A block of mass 10 kg resting on a horizontal surface is connected by a cord passing over a light frictionless pulley to a hanging block of mass 10 kg as shown in the figure. The coefficient of friction between the block and the surface is 0.5. The acceleration of the system is \[\left( \text{g }==\text{ 1}0\text{ m}/{{\text{s}}^{\text{2}}} \right)\]
A) \[\text{2}.\text{5 m}/{{\text{s}}^{\text{2}}}\]
B) \[0.\text{25 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{5 m}/{{\text{s}}^{\text{2}}}\]
D) \[0.\text{5 m}/{{\text{s}}^{\text{2}}}\]
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question_answer48) A rocket of initial mass 6000 kg ejects mass at a constant rate of 16 kg/sec with constant relative speed of 11 km/sec. What is the acceleration of the rocket a minute after the blast? (Neglect gravity)
A) \[\text{28}.\text{7 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{34}.\text{9 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{39}.\text{4 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{27}.\text{8 m}/{{\text{s}}^{\text{2}}}\]
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question_answer49) A 6000 kg rocket is set for vertical firing. If the exhaust speed is 1000 m/s, how much gas must be ejected each second to supply the thrust needed to overcome the weight of the rocket?
A) 22.2 m/s
B) 37.6 kg/sec
C) 58.8 kg/sec
D) None of these
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question_answer50) Friction between any two objects in due to
A) Attraction between them
B) Repulsion between them
C) Some adhesive forces between them
D) Irregularities on the surfaces
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question_answer51) Fuel is consumed at the rate of 100 kg/sec in a rocket. The exhaust gases are ejected at a speed of \[\text{4}.\text{5 }\times \text{ 1}{{0}^{\text{4}}}\text{ m}/\text{s}\]. Then the thrust experienced by he rocket is
A) \[\text{4}.\text{5 x 1}{{0}^{\text{6}}}\text{ N}\]
B) \[\text{5}.\text{5 x 1}{{0}^{\text{6}}}\text{ N}\]
C) \[\text{3}.\text{5 x 1}{{0}^{\text{6}}}\text{ N}\]
D) \[\text{6}.\text{72 x 1}{{0}^{\text{6}}}\text{ N}\]
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question_answer52) When a body is stationary
A) There is no force acting on it
B) The forces acting on it are not in contact with it
C) The combination of force acting on it balance each other
D) The body in vacuum
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question_answer53) When a body is in translatory equilibrium
A) The body is definitely at rest
B) The body is definitely in the state of uniform motion
C) The body will be either at rest or in the state or uniform motion
D) None of these
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question_answer54) A body is said to be under balanced forces when the resultant force acting on the body is
A) Unity
B) zero
C) Infinite
D) none of these
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question_answer55) The SI unit offered is
A) Dyne
B) gramweight
C) Newton
D) None of these
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question_answer56) 1 dyne is equal to
A) 980 gwt
B) \[\frac{1}{980}kg\] gwt
C) 980 kg wt
D) none of these
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question_answer57) When a constant force is applied to a body, it moves with uniform
A) Acceleration
B) velocity
C) Speed
D) momentum
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question_answer58) The ratio of force and acceleration is
A) Velocity
B) impulse
C) Momentum
D) none of these
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question_answer59) When a force of 1 newton acts on a mass of 1 kg that is able to move freely, the object moves with a
A) Speed of 1 \[\text{m}{{\text{s}}^{\text{1}}}\]
B) Acceleration of 1 \[\text{m}{{\text{s}}^{\text{2}}}\]
C) Speed of 1 k \[\text{m}{{\text{s}}^{\text{1}}}\]
D) None of these
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question_answer60) Passengers standing in a bus are thrown outwards when the bus takes a sudden turn,
A) Outward pull on them
B) Inertia
C) Change in momentum
D) Change in acceleration
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question_answer61) When a net force acts on an object, then the object will accelerate in the direction of force with an acceleration proportional to the
A) Force on the object
B) Velocity of the object
C) Mass of the object
D) Inertia of the object
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question_answer62) kg \[\text{m}{{\text{s}}^{\text{1}}}\]is the SI unit of
A) Impulse
B) force
C) Angular velocity
D) none of these
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question_answer63) For a particle moving along a circular path with a constant speed, the acceleration is constant in
A) Magnitude
B) Direction
C) Both magnitude and direction
D) Neither magnitude nor direction
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question_answer64) Friction is a/an
A) Selfadjusting force
B) Necessary evil
C) Important force in daily life
D) All of these
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question_answer65) Any solid will sink in water if its relative density is .....unity
A) less than
B) equal to
C) Greater than
D) none of these
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question_answer66) A cannon after firing recoils due to
A) Conservation of energy
B) Backward thrust of gases produced
C) Newton's first law of motion
D) Newton's third law of motion
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question_answer67) If a man of weight W is standing in a lift moving upward with an acceleration a, then apparent weight of the man will be
A) \[W\left( 1+\frac{a}{g} \right)\]
B) \[W\left( 1\frac{a}{g} \right)\]
C) \[W\left( 1\frac{{{a}^{2}}}{{{g}^{2}}} \right)\]
D) none of these
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question_answer68) The density of water is
A) \[\text{1}{{0}^{\text{3}}}\text{ kg}{{\text{m}}^{\text{3}}}\]
B) \[\text{1}{{0}^{2}}\text{ kg}{{\text{m}}^{\text{3}}}\]
C) \[\text{1}{{0}^{2}}\text{ kg}{{\text{m}}^{\text{3}}}\]
D) \[\text{1}{{0}^{3}}\text{ kg}{{\text{m}}^{\text{3}}}\]
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question_answer69) If a body of mass M collides against a wall with velocity V and rebounds with the same speed, then its change of momentum will be
A) Zero
B) MV
C) 2 MV
D) \[2MV\]
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question_answer70) A machine gun fires \[n\] bullets per second and the mass of each bullet is m. If speed of bullets is u, then force exerted on the machine gun will be
A) \[mng\]
B) \[mn\upsilon \]
C) \[mn\upsilon g\]
D) \[\frac{mn\upsilon }{g}\]
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question_answer71) Buoyant force depends on the
A) Depth of a liquid
B) Density of liquid
C) Colour of a liquid
D) None of these
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question_answer72) If a block has been placed an inclined plane having slope angle \[\theta \]such that the block slides down the plane at a constant speed, then coefficient of kinetic friction will be
A) \[\sin \,\theta \]
B) \[\cos \,\theta \]
C) \[g\]
D) \[\tan \,\theta \]
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question_answer73) If \[{{\mu }_{\kappa }}\]is coefficient of kinetic friction and \[{{\mu }_{s}}\] is coefficient of static friction, then
A) \[{{\mu }_{\kappa }}<{{\mu }_{s}}\]
B) \[{{\mu }_{s}}<{{\mu }_{\kappa }}\]
C) \[{{\mu }_{\kappa }}={{\mu }_{s}}\]
D) \[{{\mu }_{s}}\le {{\mu }_{\kappa }}\]
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question_answer74) Vehicles are streamlined to reduce
A) Static friction
B) kinetic friction
C) Fluid friction
D) sliding friction
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question_answer75) Relation between coefficient of friction \[\mu \] and angle of friction is
A) \[\mu =\sin \theta \]
B) \[\mu =\cos \theta \]
C) \[\mu =\tan \theta \]
D) None of these
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question_answer76) Fluid friction
A) Is independent of velocity
B) Increases with velocity
C) Decreases with velocity
D) None of these
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question_answer77) The ratio of SI units to CGS unit of density is
A) \[\text{1}{{0}^{\text{3}}}\]
B) \[\text{1}{{0}^{\text{2}}}\]
C) \[\text{1}{{0}^{\text{2}}}\]
D) \[\text{1}{{0}^{\text{3}}}\]
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question_answer78) Rolling friction
A) is independent of velocity
B) Varies with velocity
C) Increases with velocity
D) Decreases with velocity
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question_answer79) Frictional force increases when surfaces in contact are made very smooth, because of
A) Molecular force
B) Decrease in surface area
C) Decrease in irregularities
D) Increase in area
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question_answer80) Newton's first law of motion defines
A) Both inertia and force
B) Only inertia
C) Only force
D) Nothing
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question_answer81) Newton's second law of motion measures
A) Inertia
B) momentum
C) Impulse
D) force
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question_answer82) When a man in a boat in river jumps from it on river shore, the boat moves
A) Forward
B) Backward
C) To right side
D) To left side
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question_answer83) When a man sitting on a chair tries to lift himself by applying a force on the chair,
A) He cannot lift on the chair
B) He can lift easily
C) He can lift himself but very little
D) None of the above
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question_answer84) A pilot wants to fly his aeroplane in atmosphere free space
A) He cannot do it
B) He can do it easily
C) He can do it but with difficulty
D) None of the above
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question_answer85) A flying jet plane gets reaction from
A) Gravity
B) Atmosphere
C) Gravity and atmosphere
D) Gases ejected from behind
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question_answer86) Every action has reaction. These actionreaction are
A) Equal, opposite and acting on the same body
B) Equal, in the same direction and acting on same body
C) Equal, opposite and acting on different bodies
D) Equal, in same direction and acting on different bodies.
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question_answer87) When will a body under the action of several forces have zero acceleration?
A) When the vector sum of all the forces acting on the body is zero.
B) When a body is very heavy
C) When the body is very light
D) When the body is a point body
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question_answer88) A body of mass 2 kg is sliding with a constant velocity of 4 m/sec on a frictionless horizontal table. The force required to keep the body moving with the same velocity is
A) \[8\,N\]
B) \[ON\]
C) \[2\,\times \,10{{\,}^{4}}\,N\]
D) \[\frac{1}{2}N\]
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question_answer89) A ball of mass 01 kg is thrown against a wall. It strikes the wall normally with a velocity of 30 \[\text{m}{{\text{s}}^{\text{1}}}\]and rebounds from there with a velocity of 20\[\text{m}{{\text{s}}^{\text{1}}}\]. The impulse of the force exerted by the ball on the wall is
A) 0.5 Ns
B) 50 Ns
C) 5 Ns
D) 1 Ns
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question_answer90) A body of mass m moving with a constant velocity V hits another body of the same mass moving with the same velocity v but in the opposite direction and sticks to it. The velocity of the compound body after collision is
A) V
B) 2v
C) Zero
D) \[\frac{\upsilon }{2}\]
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question_answer91) In which of the following cases force may not be required to keep the
A) particle going on the circle
B) Particle going along a straight line
C) Momentum of the particle constant
D) Acceleration of the particle constant
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question_answer92) A bullet of mass a and velocity b is fired into a large block of wood of mass c, the final velocity of the system is
A) \[\frac{b}{c+b}\]
B) \[\frac{a+b}{c}a\]
C) \[\frac{a}{a+c}a\]
D) \[\frac{a+c}{a}b\]
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question_answer93) A force of 12 N gives an object an acceleration of\[\text{4 m}/{{\text{s}}^{\text{2}}}\]. The force required to give it an acceleration of \[\text{1}0\text{ m}/{{\text{s}}^{\text{2}}}\]is
A) 15 N
B) 20 N
C) 25 N
D) 30 N
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question_answer94) A weight of 290 N and another 200 N are suspended by a rope on either side of a frictionless pulley. The acceleration of each weight is
A) \[\text{1}\text{.5 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{1}\text{.8 m}/{{\text{s}}^{\text{2}}}\]
C) \[\text{2}\text{.2 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{2}\text{.5 m}/{{\text{s}}^{\text{2}}}\]
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question_answer95) Two boxes, one of mass 20 kg and the other of mass 40 kg, are sliding down a frictionless inclined plane that makes an angle of \[30{}^\circ \] with the horizontal. The respective acceleration in \[\text{m}/{{\text{s}}^{\text{2}}}\] are
A) \[\text{9}\text{.8},\text{9}\text{.8}\]
B) \[\text{4}\text{.9},\text{9}\text{.8}\]
C) \[\text{9}\text{.8},\text{4}\text{.9}\]
D) \[\text{4}\text{.9},\text{4}\text{.9}\]
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question_answer96) Two masses, each equal to m, are attached to one another by a massless string passing over a smooth pulley. The tension in the string is
A) \[mg\]
B) \[2m\]
C) \[\frac{mg}{2}\]
D) Zero
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question_answer97) What force should be applied on a 5 kg body s that it has a downward acceleration of\[\text{4m}/{{\text{s}}^{\text{2}}}\]?
A) 69 N upwards
B) 69 N downwards
C) 29 N upwards
D) 29 N downwards
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question_answer98) A body rolling freely on the surface of the earth eventually comes to rest because
A) It has mass
B) It suffers friction
C) It has inertia of rest
D) It has momentum
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question_answer99) A body of mass 50 kg acquires a speed of 20 m/s under a force of 100 n in time
A) 5 s
B) 10 s
C) 15 s
D) 20 s
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question_answer100) The mass of balloon and its contents is M It is descending with an acceleration a. By how much the mass should be decreased, keeping the volume constant, so that the balloon starts ascending with the same acceleration?
A) \[\frac{a}{a+g}M\]
B) \[\frac{g}{a+g}M\]
C) \[\frac{2a}{a+g}M\]
D) \[\frac{2g}{a+g}M\]
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question_answer101) Two blocks A and B, having masses m, and m respectively, are placed in contact on a smooth horizontal surface. A force F is applied horizontally on A. The contact force between A and B is
A) \[\frac{{{m}_{1}}}{{{m}_{2}}}F\]
B) \[\frac{{{m}_{2}}}{{{m}_{1}}}F\]
C) \[\frac{{{m}_{1}}F}{{{m}_{1}}+{{m}_{2}}}\]
D) \[\frac{{{m}_{2}}F}{{{m}_{1}}+{{m}_{2}}}\]
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question_answer102) A block of mass 9 kg, lying on a frictionless table is connected to a block of mass 1 kg by means of a string which passes over a frictionless pulley as shown. The tension in the string is \[\left( \text{g}=\text{1}0\text{ m}/{{\text{s}}^{\text{2}}} \right)\]
A) 1N
B) 4N
C) 7N
D) 9N
E) None of these
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question_answer103) The minimum acceleration with which a fireman slide down a rope of breaking strength twothird of his weight is
A) Zero
B) \[\frac{g}{3}\]
C) \[\frac{2g}{3}\]
D) \[g\]
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question_answer104) A disc of mass 10 g is kept floating horizontally by throwing 10 marbles per second against it from below. The marbles strike the disc normally and rebound downwards with the same speed If the mass of each marble is 5 g, the velocity with which the marbles are striking the disc is\[(g=9.8\,m/{{s}^{2}})\].
A) 0.98 m/s
B) 9.8 m/s
C) 1.96 m/s
D) 19.6 m/s
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question_answer105) A monkey of mass 40 kg climbs on a massless rope of breaking strength 600 N. The rope will break if the monkey \[\left( \text{g}=\text{1}0\text{ m}/{{\text{s}}^{\text{2}}} \right)\]
A) Climbs up with a uniform speed of 5 m/s
B) Climbs up with an acceleration of \[\text{6 m}/{{\text{s}}^{\text{2}}}\]
C) Climbs down with an acceleration of \[\text{4 m}/{{\text{s}}^{\text{2}}}\]
D) Climbs down with a uniform speed of \[\text{5 m}/\text{s}\]
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question_answer106) A body is projected up a \[40{}^\circ \] rough inclined plane. If the coefficient of friction is 05, then the retardation of the block is
A) \[\frac{g}{2\sqrt{2}}\]
B) \[\frac{g}{\sqrt{2}}\]
C) \[\frac{3g}{2\sqrt{2}}\]
D) \[\frac{g}{2}\]
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question_answer107) A block of mass 5 kg is placed on a rough inclined plane. The inclination of the lane is gradually increased till the block just begin to slide down The inclination of the plane is then 3 in 5 The coefficient of friction between the block and the plane is \[\left( \text{g}=\text{ 1}0\text{ m}/{{\text{s}}^{\text{2}}} \right)\]
A) 3/5
B) 3/4
C) 4/5
D) 2/3
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question_answer108) In the above question, the minimum force required to move the block up the plane at this inclination is
A) 30 N
B) 40 N
C) 60 N
D) 120 N
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question_answer109) A body rests on a rough horizontal plane. A force is applied to the body directed towards the plane at an angle \[\phi \]with the vertical. The body can be moved along the plane.
A) Only \[\phi \]is more than the angle of friction
B) Only \[\phi \] is less than the angle of friction
C) Only \[\phi \] is equal to the angle of friction
D) For all values of \[\phi \]
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question_answer110) A particle of mass 100 g is suspended from a light string. The string is moved [a] Upwards, and [b] Downwards with an acceleration of\[\text{5 m}/{{\text{s}}^{\text{2}}}\]. If \[{{T}_{u}}\] and \[{{T}_{d}}\] are the tension in the string during upward and downward motion respectively, then \[{{T}_{u}}{{T}_{d}}\] is equal to
A) 1N
B) 0.5 N
C) 0.98 N
D) 1.96 N
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question_answer111) The mass of a body measured by a physical balance in a lift at rest is found to be m. If the lift is going up with an acceleration a, its mass will be measured as
A) \[m\left( 1\frac{a}{g} \right)\]
B) \[\left( 1+\frac{a}{g} \right)\]
C) \[m\]
D) Zero
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question_answer112) A string is compressed between two toycarts of masses \[{{m}_{1}}\] and \[{{m}_{2}}\]. When the toycarts are released, the spring exerts on each equal and opposite average forces for the same time\[t\]. If the coefficient of friction \[\mu \] between the ground and the carts are equal, then the displacement of the two toycarts are in the ratio
A) \[\frac{{{S}_{1}}}{{{S}_{2}}}=\frac{{{m}_{2}}}{{{m}_{1}}}\]
B) \[\frac{{{S}_{1}}}{{{S}_{2}}}=\frac{{{m}_{1}}}{{{m}_{2}}}\]
C) \[\frac{{{S}_{1}}}{{{S}_{2}}}={{\left( \frac{{{m}_{2}}}{{{m}_{1}}} \right)}^{2}}\]
D) \[\frac{{{S}_{1}}}{{{S}_{2}}}={{\left( \frac{{{m}_{2}}}{{{m}_{1}}} \right)}^{2}}\]
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question_answer113) A block of mass 1 kg moving with a speed of \[\text{2 m}{{\text{s}}^{\text{1}}}\]collides with and sticks to another block of mass 2 kg which was initially at rest. After the collision
A) The momentum of the system is less than \[\text{2}\,\text{kg}\,\text{m}{{\text{s}}^{\text{1}}}\]9
B) The kinetic energy of the system is\[\frac{2}{3}J\]
C) The kinetic energy of the system is \[2J\]
D) None of these
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question_answer114) A bullet of mass \[{{m}_{1}}\] is fired into a block mass \[{{m}_{2}}\] suspended like a pendulum. The block, initially at rest, is raised to a height h, after the impact. The velocity of the bullet is
A) \[\left( 1+\frac{{{m}_{1}}}{{{m}_{2}}} \right)\sqrt{gh}\]
B) \[\frac{{{m}_{1}}}{{{m}_{2}}}\sqrt{2gh}\]
C) \[\left( 1+\frac{{{m}_{1}}}{{{m}_{2}}} \right)\sqrt{2gh}\]
D) \[\left( 1+\frac{{{m}_{2}}}{{{m}_{1}}} \right)\sqrt{2gh}\]
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question_answer115) Force of friction between the floor and a wooden block of mass M and area of surface A is F. Force of friction between the floor and a block of mass 2 M and area of surface A will be
A) 2 F
B) F
C) \[\frac{F}{2}\]
D) \[\sqrt{2}F\]
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question_answer116) A diwali rocket is ejecting 0.05 kg of gases per second at a velocity of 400 m/sec. The accelerating force on the rocket is
A) 20 dynes
B) 20 Newtons
C) 20 kg wt
D) 10 Newtons
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question_answer117) A bullet fired into a wall loses half of its velocity after penetrating 3 cm. Further it can penetrate a maximum of
A) 3 cm
B) 2 cm
C) 1cm
D) 0.5cm
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question_answer118) A body of mass 100 g is sliding from an inclined plane of inclination \[30{}^\circ \]. What is the frictional force experienced, if \[\mu =1.7\]?
A) \[1.7\times \sqrt{2}\times \frac{1}{\sqrt{3}}N\]
B) \[1.7\times \sqrt{3}\times \frac{1}{2}N\]
C) \[1.7\times \sqrt{3}N\]
D) \[1.7\times \sqrt{2}\times \frac{\sqrt{2}}{\sqrt{3}}N\]
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question_answer119) Which of the following is not a perfectly inelastic collision?
A) Striking of two glass balls
B) A bullet striking a bag of sand
C) An electron captured by a proton
D) A man jumping into a moving cart
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question_answer120) A plank, 8 m long, has one end 1 m higher than the other. What minimum force parallel to the plank will be necessary to push a box up it, the box and its contents having a mass of 100 kg and the coefficient of sliding friction between it and the plank being 0.3 ?
A) 50.2 kgf
B) 25.5 kgf
C) 75.0 kgf
D) 42.3 kgf
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question_answer121) A truck and a car moving with same kinetic energy are stopped by equal retarding force. Which of them will be stopped in shorter distance?
A) Truck
B) Car
C) Both simultaneously
D) Data not sufficient
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question_answer122) A man weighing 80 kg is standing in a trolley weighing 320 kg. The trolley is resting on frictionless horizontal rails. If the man starts walking on the trolley with a speed of 1 m/s, then after 4 sec his displacement relative to the ground will be
A) 5 m
B) 4.8 m
C) 3.2m
D) 3.0 m
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question_answer123) A jet of water (density \[\rho \]) with a crosssectional area a is striking against a wall at an angle \[\theta \] to the normal and rebounds elastically. If the velocity of water in the jet is v, the normal force acting on the wall is
A) \[2\,\,a{{\upsilon }^{2\,\,}}\,p\,\,\cos \,\theta \]
B) \[a{{\upsilon }^{2\,\,}}\,p\,\,\cos \,\theta \]
C) \[2\,\,\,a\upsilon \,\,p\,\,\cos \,\theta \]
D) \[a\upsilon \,\,p\,\,\cos \,\theta \]
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question_answer124) A bucket containing water of depth 15 cm is kept in a lift which is moving upwards with an acceleration 2 g. The pressure at the bottom of the bucket is
A) \[\text{1}0\text{ g dyne c}{{\text{m}}^{\text{2}}}\]
B) \[\text{2 dyne c}{{\text{m}}^{\text{2}}}\]
C) \[\text{4}0\text{ g dyne c}{{\text{m}}^{\text{2}}}\]
D) \[\text{45 g dyne c}{{\text{m}}^{\text{2}}}\]
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question_answer125) Two masses m and 2m are attached with each other by a rope passing over a frictionless and massless pulley. If the pulley is accelerated upwards with an acceleration a, what is the value of T ?
A) \[\frac{g+a}{3}\]
B) \[\frac{ga}{3}\]
C) \[\frac{4m(g+a)}{3}\]
D) \[\frac{m(ga)}{3}\]
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question_answer126) A body of mass 2 kg is initially moving with a velocity of 4 m/sec. Now a force of 1.25 Newtons acts for 8 sec. Then a force of 2.5 N acts for 8 sec. The final velocity of the body is
A) 12.55 m/sec
B) 17 m/sec
C) 19 m/sec
D) 25 m/sec
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question_answer127) A body is freely released from point A so that it slides down the smooth inclined plane AB and then along the rough horizontal surface BC and comes to point C with 4 m/sec. Then the coefficient of friction over the rough surface is
A) 0.2
B) 0.4
C) 0.65
D) 0.75
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question_answer128) Three bodies nip \[{{m}_{1}},{{m}_{2}}\] and \[{{m}_{3}}\]nip of mass 10 kg, 20 kg and 30 kg respectively are lying on a frictionless horizontal table and are connected by strings as shown in the figure. These are pulled towards the right with a force of 60 N. Then the tension \[{{T}_{1}},\] and \[{{T}_{2}},\] will respectively be
A) 10 N, 20 N
B) 20 N, 20 N
C) 10 N, 50 N
D) 10 N, 30 N
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question_answer129) An alphaparticle is emitted by U238 nucleus with a speed of \[\text{1}.\text{5 x 1}{{0}^{\text{7}}}\] m/sec. The recoil speed of the remaining nucleus will be
A) \[\text{2}.\text{4 x 1}{{0}^{\text{5}}}\text{ m}/\text{sec}\]
B) \[0.\text{24 x 1}{{0}^{\text{5}}}\text{ m}/\text{sec}\]
C) \[\text{24 x 1}{{0}^{\text{5}}}\text{ m}/\text{sec}\]
D) \[\text{245 x 1}{{0}^{\text{5}}}\text{ m}/\text{sec}\]
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question_answer130) Two freely hanging weights, each having a mass of 60 gm, are connected by a light thread which passes over a fixed pulley. The mass of the pulley and frictional losses are negligible. If a 10 gm weight is now added to one of the weights, its downward acceleration, in\[\text{cm}/\text{se}{{\text{c}}^{\text{2}}}\], will be approximately
A) 32
B) 80
C) 106
D) 980
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question_answer131) A cricket ball of mass 150 gram moving with a velocity of 12 m/s strikes against the bat. It renounces with a velocity of 20 m/s. The ball remains in touch with the bat for 0.01 second. The average force applied by the bat on the ball is
A) 840 Newton
B) 480 Newton
C) 804 Newton
D) 408 Newton
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question_answer132) Action and reaction act on
A) Same body in opposite directions
B) Same body in the same direction
C) Different bodies in opposite directions
D) Different bodies but in the same direction
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question_answer133) A block of mass m, attached to a spring of spring constant k, oscillates on a smooth horizontal table. The other end of the spring is fixed to a wall. If it has a speed v when the spring is at its natural length, how far will it move on the table before coming to an instantaneous rest
A) \[\sqrt{\frac{\upsilon m}{k}}\]
B) \[\sqrt{\frac{\upsilon k}{m}}\]
C) \[u\sqrt{\frac{k}{m}}\]
D) \[u\sqrt{\frac{m}{k}}\]
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question_answer134) It is easier to draw up wooden block along an inclined plane than have it up vertically, principally because
A) The friction is reduced
B) The mass becomes smaller
C) Only a part of weight has to be overcome
D) g becomes smaller.
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question_answer135) A ball of mass 0.2 kg moves with a velocity of 20 m/s and it stops in 0.1 s, then the force on the ball is
A) 40 N
B) 20 N
C) 4N
D) 2 N
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question_answer136) What maximum horizontal force can be applied to the lower block so that the two blocks move without separation ?
A) \[(M+m)({{\mu }_{1}}+{{\mu }_{2}})g\]
B) \[(Mm)({{\mu }_{1}}+{{\mu }_{2}})g\]
C) \[(M+m)({{\mu }_{1}}{{\mu }_{2}})g\]
D) \[(Mm)({{\mu }_{1}}{{\mu }_{2}})g\]
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question_answer137) Which one of the following statement does not hold good when two balls of masses \[{{m}_{1}}\] and \[{{m}_{2}}\] undergo elastic collision?
A) When \[{{m}_{1}}<{{m}_{2}}\] and \[{{m}_{2}}\] at rest, there will be maximum transfer of momentum.
B) When \[{{m}_{1}}={{m}_{2}}\] and \[{{m}_{2}}\] at rest, there will be maximum transfer of K.E.
C) When collision is oblique and \[{{m}_{2}}\] at rest with \[{{m}_{1}}={{m}_{2}}\], after collision the ball moves in opposite direction.
D) None of these
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question_answer138) A boy sitting on the top most berth in the compartment of a train which is just joint to stop on a railway station, drops an apple aiming at the open hand of his brother situated vertically below his hands at a distance of about 2m. The apple will fall
A) In the hand of his brother.
B) Slightly away from the hands of his brother in the direction of motion of the train.
C) Slightly away from the hands of his brother in the direction opposite to the direction of motion of the train.
D) None of the above.
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question_answer139) A stretching force of 1000 Newton is applied at one end of a spring balance and an equal stretching force is applied at the other end at the same time. The reading of the balance will be
A) 2000 N
B) 0 N
C) 1000N
D) 500N
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question_answer140) Two mass A and B each of mass M are fixed together by a massless spring A force F acts on the mass B as shown in figure. At the instant shown, the mass A has acceleration a. What is the acceleration of mass B ?
A) \[\left( \frac{F}{M} \right)a\]
B) \[a\]
C) \[a\]
D) \[\left( \frac{F}{M} \right)\]
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question_answer141) A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. If a force of 2.8 N is applied on the block parallel to the floor, the force of friction between the block and floor \[\left( \text{taking g }=\text{ 1}0\text{ m}/\text{se}{{\text{c}}^{\text{2}}} \right)\] is
A) 2.8 N
B) 8N
C) 2N
D) Zero
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question_answer142) A block has been placed on an inclined plane. The slope angle 6 of the plane is such that the block slides down the plane at a constant speed. The coefficient of kinetic friction is equal to
A) \[\sin \,\,\theta \]
B) \[\cos \,\,\theta \]
C) \[g\]
D) \[\tan \,\,\theta \]
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question_answer143) A body of mass 60 kg is dragged with just enough force to start moving on a rough surface with coefficients of static and kinetic frictions 0.5 and 0.4 respectively. On applying the same force, what is the acceleration?
A) \[0.\text{98 m}/{{\text{s}}^{\text{2}}}\]
B) \[\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}}\]
C) \[0.\text{54 m}/{{\text{s}}^{\text{2}}}\]
D) \[\text{5}.\text{292 m}/{{\text{s}}^{\text{2}}}\]
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question_answer144) Pushing force making an angle \[\theta \]to the horizontal is applied on a block of weight W placed on a horizontal table. If the angle of friction is\[\phi \] , the magnitude of force required to move the body is equal to
A) \[\frac{W\,\cos \phi }{\cos \,(\theta \phi )}\]
B) \[\frac{W\,\sin \phi }{\cos \,(\theta \phi )}\]
C) \[\frac{W\,\tan \phi }{\sin (\theta \phi )}\]
D) \[\frac{W\,\sin \phi }{g\sin (\theta \phi )}\]
E) None of these
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question_answer145) A mass m rest on a horizontal surface. The coefficient of friction between the mass and the surface is p. If the mass is pulled by a force P 3. shown in the figure, the limiting friction between mass and the surface will be
A) \[\mu \,mg\]
B) \[\mu \,\left[ mg\left( \frac{\sqrt{3}}{2} \right)F \right]\]
C) \[\mu \,\left[ mg\left( \frac{F}{2} \right) \right]\]
D) \[\mu \,\left[ mg+\left( \frac{F}{2} \right) \right]\]
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question_answer146) A block of mass 0.1 kg is held against a wall by applying a horizontal force of 5 N on the lock. If the coefficient of friction between the block and the wall is 0.5, the magnitude of the frictional force acting on the block is
A) 2.5 N
B) 0.98 N
C) 4.9 N
D) 0.49 N
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question_answer147) A free body of mass 8 kg is travelling at 2 metres per second in a straight line. At a certain instant, the body splits into two equal parts due to internal explosion which releases 16 joules of energy. Finally
A) Both parts continue to move in the same direction as that of the original body.
B) One part comes to rest and the other moves in the same direction as that of the original body.
C) One part comes to rest and the other moves in the direction opposite to that of the original body.
D) one part moves in the same direction and the other in the direction opposite to that of the original body.
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question_answer148) Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed v along the groove collide with this row on extreme left side end. Then
A) One ball from the right end will move on with speed \[\varepsilon \upsilon \], all the other remains at rest
B) Two balls from the extreme right will move on the speed u each and the remaining balls will be at rest.
C) All the balls will start moving to the right with.
D) All the six balls originally at rest will moves on with speed \[\frac{\upsilon }{6}\] each and the two incident ball will come to rest.
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question_answer149) Two perfectly elastic particles A and B of equal masses travelling along the line joining them with velocity 15 m/s and 10 m/s respectively collide. Their velocities after the elastic collision will be (in m/s) respectively
A) 0 and 25
B) 5 and 20
C) 10 and 15
D) 20 and 5
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question_answer150) When a horse pulls a wagon, the force that causes the horse to move forward is the force
A) He exerts on the wagon
B) The wagon exerts on him
C) The ground exerts on him
D) He exerts on the ground.
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question_answer151) A parachutist of weight W strikes the ground with his legs fixed and comes to rest with an upward acceleration of 3 g. Force exerted by him on the ground during landing is
A) W
B) 2W
C) 3W
D) 4W
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question_answer152) A monkey is descending from the branch of a tree with constant acceleration. If the breaking strength is 75% of the weight of the monkey, the minimum acceleration with which monkey can slide down without breaking the branch is
A) g
B) \[\frac{3g}{4}\]
C) \[\frac{g}{4}\]
D) \[\frac{g}{2}\]
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question_answer153) A car is moving on a straight road with a speed \[{{V}_{0}}\]. If the coefficient of friction between the tyres and the road is p, the distance travelled by the car before it comes to rest is
A) \[\frac{{{V}_{0}}^{2}}{2\mu g}\]
B) \[\left( \frac{{{V}_{0}}^{2}}{\mu g} \right)\]
C) \[\frac{{{V}_{0}}}{\mu g}\]
D) \[\frac{{{V}_{0}}^{2}}{\mu g}\]
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question_answer154) A machinegun fires 20 bullets per second into a target. Each bullet weight 150 gm and has a speed of 800 m/sec. The force necessary to hold the gun in position is
A) 800 N
B) (6) 1000 N
C) 1200 N
D) 2400 N
E) None of these
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question_answer155) A sphere of mass m moving with a constant velocity u hits another stationary sphere of same mass. If e is the coefficient of restitution, then ratio of velocities of the two spheres after collision will be
A) \[\frac{1e}{1+e}\]
B) \[\frac{1+e}{1e}\]
C) \[\frac{e1}{1e}\]
D) \[\frac{e1}{1+e}\]
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question_answer156) A particle moves in the xy plane under the action of a force \[\overrightarrow{F}\] such that the value of its linear momentum \[\overrightarrow{P}\] at any time t is \[{{p}_{X}}=2\] cos t and the angle \[\theta \] between \[\overrightarrow{F}\] and \[\overrightarrow{P}\] at any time t will be
A) \[90{}^\circ \]
B) \[0{}^\circ \]
C) \[180{}^\circ \]
D) \[30{}^\circ \]
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