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Newton’s Laws of Motion, , Laws of Motion (Section-1), , Single choice questions (Level 0)

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1.The engine of a car produces acceleration 4m/s2, in the car. If this car pulls another car of some, mass, what will be the acceleration produced, (a) 8 m/s2 (b) 2 m/s2 (c) 4 m/s2 (d) ½ m/s2, 2. If a bullet of mass 5 gm moving with velocity, 100m/s,, Then the, block is, , penetrates the wooden block up to 6cm., average force imposed by the bullet on the, , (a) 8300 N, , (b) 417 N, , (c) 830 N, , (d) Zero, , 3. A bird weighs 2kg and in inside a closed cage of 1kg., If it starts flying, then what is the weight of the bird, and cage assembly, (a) 1.5 k g N (b) 2.5 kg N (c) 3 kg N (d) 4 kg N, 4. A particle is moving with a constant speed along, , a straight line path. A force is not required to, (a) Increase its speed, (b) Decrease the momentum, (c) Change the direction, (d) Keep it moving with uniform velocity?, 5.. The displacement versus time graph for a body, moving, in, X, straight line is, e, shown, in, d, figure. Which, of, the, c, b, following, regions, represents the, a, Time, Y, motion when, no force is, acting on the body, (a) ab, (b) bc, (c) cd, (d) de, 6. In which of the following cases the net force is not, zero?, (a)a kite skill fully held stationary in the sky., (b)a ball freely falling from a height, (c)an aeroplane rising upwards at an angle of 45°, with the horizontal with a constant speed, (d)a cork floating on the surface of water., , 7. Two masses M, and m are, M, m, F, connected by, a weightless, string. They are pulled by a force F on a, frictionless horizontal surface. The tension in, the string will be, FM, F, F, Fm, (a), b), (c), (d), mM, M m, M m, M m, 8. In the above question, the acceleration of mass m, is, F, F T, 10 Kg, (a), (b), (c), m, m, 5 Kg, F T, F, (d), m, M, 9. Two masses of 10 kg and 5 kg are, suspended from a fixed support as, , 150 N, , shown in the figure. The system is pulled down with, a force of 150 N attached to the lower mass. The, string attached to the support breaks and the system, accelerates downwards. If the downward force, continues to act, what is the acceleration of the, system?, (a) 20 ms2 (b) 10 ms2 (c) 5 ms2, (d) zero, 10. A forces F1 acts on a particle so as to accelerate it, from rest to a velocity v. The force F1 is then, replaced by F2 which decelerates it to rest, (a) F1 must be equal to F2 (b) F1 may be equal to F2, (c) F1 must be unequal to F2 (d) none of these, 11.The reaction force between the floor and a man of, mass 60 kg standing on a lift that is accelerating, downwards at a uniform acceleration of 4 m/s² will, be, (a) 840 N, (b) 360 N (c) 500 N, (d) 300 N, , 12. An elevator weighing 6000 kg is pulled upward, by a cable with an acceleration of 5ms-2. Taking, g to be 10ms-2, then the tension in the cable is, (a) 6000 N (b) 9000 N (c) 60000 N (d) 90000 N, 13. A ship of mass 3  107 kg initially at rest, is pulled, by a force of 5  104 N through a distance of 3m., Assuming that the resistance due to water is, negligible, the speed of the ship is, (a) 1.5 m/sec. (b) 60 m/sec (c) 0.1 m/sec (d) 5, m/sec, 14. When forces F1 F2, F3 are acting on a particle of, mass m such that F2 and F3 are mutually, perpendicular, then the particle remains stationary., If the force F1 is now removed then the, acceleration of the particle is, (a) F1/m (b) F2F3/mF1 (c) (F2 – F3)/m (d) F2/m., 15. 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 (a) 8 : 1, (b) 9 : 7, (c) 4 :, 3 (d) 5 : 3, 16. Three identical blocks of masses m = 2 kg are, drawn by a force F = 10.2 N on a frictionless, surface, then what is the, , C, , B, , A, , F, , tension (in N) in the string between the blocks B, and C?, (a) 9.2, (b) 3.4, (c) 4, (d) 9.8, 17. A block of mass M is pulled along a horizontal, friction surface by a rope of mass m. If a force P is, applied at the free end of the rope, the force exerted, Pm, by the rope on the block, (a), (b), Mm, PM, Pm, (c) P (d), Mm, mM

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20. A force vector applied on a mass is represented, , as F  6iˆ  8 ˆj  10kˆ and accelerates with, 1m/s2. What will be the mass of the body, (a) 10 2 kg (b) 2 10 kg (c)10kg (d) 20 kg, , 18. A body is slipping from an inclined plane of, height h and length l. If the angle of inclination, θ, the time taken by the body to come from the, top to the bottom of this inclined plane is, , 21. Three forces start acting simultaneously on a, particle moving with velocity v . These forces are, represented in magnitude and direction by the three, sides of a triangle ABC(as shown)a. The particle, will now move with velocity, (a) less than v, (b) greater than v, (c) v in the direction of the largest force BC, (d) v ,remaining unchanged, , 22. A body of mass 5 kg starts from the origin with an, , , 2h, 2l, 1, 2h, 2h, (b), (c), (d) sinθ, g, g, sin  g, g, 19. An object start sliding on a frictionless inclined, plane and from same height another object start, falling freely, (a) Both will reach with same speed, (b) Both will reach with the same acceleration, (c) Both will reach in same time, (a), , , , , , initial velocity u = 30 i +40 j ms-1. If a constant, , , , force F   i  5 j  N acts on the body, the time, , , in which the y- component of the velocity, becomes zero is, (a) 5 seconds, (b) 20 seconds, (c) 40 seconds, (d) 80 seconds, , Friction(Section-2), , Single choice questions (Level 0), 1. A body of weight 500 N is, placed on a rough surface. If, A, the force required to move, the body on the surface is, 300 N the coefficient of, friction is, B, C, (a) 0.6, (b) 1.2, (c) 0.3 (d) 1.67, 2. A brick of mass 2 kg just begins to slide down an, inclined plane at an angle of 45° with the horizontal., The force of friction will be, , (a) 19.6 Sin 45°, (b) 119.6 cos 45°, (c) 9.8 sin 45°, (d) 9.8 cos 45°, 3. On the horizontal surface of a truck a block of mass, 1 kg is placed (µ = 0.6) and truck is moving with, acceleration 5 m/s². The frictional force on the, block will be, (a) 5 N, (b) 6 N, (c) 5.88 N, (d) 8 N, 4. A body of mass 10 kg lies on a rough horizontal, surface. When a horizontal force of F Newton acts, on it, it gets an acceleration of 5 m/s² and when the, horizontal force is doubled, it gets an acceleration, of 18 m/s². Then the coefficient of friction between, the body and the horizontal surface is (assume g =, 10 m/s²), (a) 0.2, (b) 0.8, (c) 0.4, (d) 0.6, 5. A body is projected along a rough horizontal, surface with a velocity 6 m/s. If the body comes to, rest after travelling a distance 9 m, the coefficient, of sliding, friction is (g = 10 m/s²), (a) 0.5, (b) 0.6, (c) 0.4, (d) 0.2, 6., On a rough horizontal surface, a body of mass 2, kg is given a velocity of 10 m/s. If the coefficient of, friction is 0.2 and g = 10 m/s², the body will stop after

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covering a distance of, (a) 10 m, (b) 25 m, (c) 50 m, (d) 250 m, 7. A body of weight 64 N is pushed with just enough, force is start it moving across a horizontal floor and, the same force continues to act afterwards. If the, coefficients of static and dynamic friction are 0.6, and 0.4 respectively, the acceleration of the body, will be (acceleration due to gravity = g), (a) g/6.4, (b) 0.64 g, (c) g/32, (d) 0.2 g, 8. A particle is projected up along a rough inclined, plane of inclination 45° with the horizontal. If the, coefficient of friction is 0.5, the retardation is (g =, acceleration due to gravity), g, 3g, g, g, (a), (b), (c), (d), 2, 2, 2 2, 2 2, 9. A block of weight 200 N is pulled along a rough, horizontal surface at constant speed by a force 100, N acting at an angle 30° above the horizontal. The, coefficient of kinetic friction between the block and, the surface is, (a) 0.43, (b) 0.58, (c) 0.75, (d), 0.83, 10. The force that prevents the relative motion between, the layers of a liquid is called:, (a) sliding friction, (b) contact friction, (c) static friction, (d) none of the above, 11. In a situation the contact force by a rough horizontal, surface on a body placed on it has constant, magnitude. If the angle between this force and the, vertical is decreased, the frictional force between, the surface and the body will, (a) increases, (b) remain the same, (c) decreases, (d) may increase or decrease, 12. A force of 98 N is required to just start moving a, body of mass 100 kg over ice. The coefficient of, static friction is, (a) 0.6, (b) 0.4, (c) 0.2, (d) 0.1, 13. A block of 1 kg is stopped against a wall by, applying a force F perpendicular to the wall. If µ =, 0.2 then minimum value of F will be, (a) 980 N, (b) 49 N (c) 98 N, (d) 490 N, 14. A 20 kg block is initially at rest on a rough, horizontal surface. A horizontal force of 75 N is, required to set the block is motion. After it is in, motion, a horizontal force of 60 N is required to, keep the block moving with constant speed. The, coefficient of static friction Is, (a) 0.38 (b) 0.44, (c) 0.52, (d) 0.60, 15. A horizontal force of 10 N is necessary to just hold, a block stationary against a, wall. The coefficient of friction, between the block and the wall, 10 N, is 0.2. the weight of block is, (a) 2 N, (b) 20 N, (c), 50 N (d) 100 N, 16. 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) 0.98 m/s² (b) 9.8 m/s² (c) 0.54 m/s² (d) 5.292, m, 17. The coefficient of static, friction, µs , between block, A of mass 2 kg, and the table as shown in, 2kg, A, 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 B, pulley are assumed to be smooth and mass, less. (g=10 m/s2), (a) 2.0 kg, (b) 4.0 kg, (c) 0.2 kg (d) 0.4 kg, 18. A block of mass M = 5 kg is resting on a rough, horizontal surface for which the coefficient of, friction is 0.2. When a force F= 40 N is applied, the, acceleration of the block will be (g=10 m/s2), (a) 5.73 m/sec2, (b) 8.0 m/sec2, 2, (c) 3.17 m/sec, (d) 10.0 m/sec2, 2kg, , A, , B, , 19. A block of mass 2kg rests on a inclined plane, making an angle of 300 with the horizontal. The, coefficient of static friction between the block and, the plane is 0.7. The frictional force on the block is, (b) 0.7  9.8 , , (a) 9.8 N, , 3N, , (c) 9.8  3N, (d) 0.7  9.8 N, 20. A marble block of mass 2 kg lying on ice when, F, given a velocity of 6 m/s is stopped by friction, o, in 10s.Then the coefficient of, 30, friction is, M, (a) 0.01, (b) 0.02, (c) 0.03, (d) 0.06, 21. A body of mass 10 kg is lying on a rough plane, inclined at an angle of 300 to the horizontal and the, coefficient of friction is 0.5. the minimum force, required to pull the body up the plane is, (a) 914 N (b) 91.4 N (c) 9.14 N, (d) 0.914 N, 22. A body of 5 kg weight kept on a rough inclined, plane of angle 300 starts sliding with a constant, velocity. Then the coefficient of friction is (assume, g =10 m/s2), (a) 1/ 3, , (b) 2/ 3, , (c), , 3, , (d) 2 3

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23. Two cars of unequal masses use similar tyres. If, they are moving at the same initial speed, the, minimum stopping distance, (a) is smaller for the heavier car, (c) is same for both cars, (b)is smaller for the lighter car, (d) depends on the volume of the car, 24. In order to stop a car in shortest distance on a, horizontal road, one should, (a) apply the brakes very hard so that the wheels, stop rotating, (b) apply the brakes hard enough to just prevent, slipping, (c) pump the brakes (press and release), (d) shut the engine off and not apply brakes, 25.A block of mass M is placed on a rough inclined, plane of inclination  kept on the floor of a lift. The, coefficient of friction between the block and, inclined plane is µ. With what acceleration the, block will slide down the inclined plane when the, lift falls freely?, (a) zero, (b) g sin  µg cos, (c) g sin + µg cos, (d) none of the above., 26. A block of mass 0.1 kg is held against a wall by, applying a horizontal force of 5 N on the block. 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, [IIT 1994Screening], (a) 2.5 N, (b) 0.98 N, (c) 4.9 N, (d) 0.49 N, 27. A mass m rest on a horizontal surface. The, coefficient of friction between the, mass and the surface is µ. If the, 30°, mass is pulled by a force F as, m, shown in the figure the limiting, , friction between mass and the surface will be, , 3 , (b) µmg , F, 2 , , F, , (d) µmg  , 2, , , (a) µmg, F, , (c) µmg  , 2, , , 28. A block is placed on a rough inclined plane of, inclination  = 30°. If the force to drag it along its, plane is to be smaller than to lift it. The coefficient, of friction µ should be less than, (a), , 1, 2, , (b), , 3, 2, , (c), , 2, 3, , (d), , 1, 3, , 29. A block rests on a rough inclined plane making an, angle of 30 with the horizontal. The coefficient of, static friction between the block and the plane is 0.8., If the frictional force on the block is 10 N, the mass, of the block (in kg) is (take g = 10 m/s2), (a) 1.6, , (b) 4.0, , (c) 2.0, , (d) 2.5, , 30. Consider a car moving on a straight road with a, speed of 100 m/s. The distance at which car can be, stopped is [µk =0.5], (a) 100 m (b) 400 m (c) 800 m, (d) 1000 m, , 31 A body of mass m moves with velocity v on a plane, whose coefficient of friction is µ. If the body covers, a distance s before coming to rest, then value of v is, (a) µ gs (b) 2µ gs (c) 2 µ gs (d) 2 2µ gs, , Pseudo Force:(Section 3)

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1. When a train stops suddenly, passengers in the, running train feel an instant jerk in the forward, direction because, (a) The back of seat suddenly pushes the, passengers forward, (b) Inertia of rest stops the train and takes the, body forward, (c) Upper part of the body continues to be in the, state of motion whereas the lower part of the, body in contact with seat remains at rest, (d) Nothing can be said due to insufficient data, 2. A man getting down a running bus falls forward, because, (a) Due to, inertia of rest, road is left behind and man, reaches forward, (b) Due to inertia of motion upper part of body, continues to be in motion in forward direction, while feet come to rest as soon as they touch, the road, (c) He leans forward as a matter of habit, (d) Of the combined effect of all the three factors, stated in (a), (b) and (c), 3. A coin is dropped in a lift. It takes time t1 to, reach the floor when lift is stationary. It takes, , time t2 when lift is moving up with constant, acceleration. Then, (a) t1 > t2, (b) t2 > t1 (c) t1 = t2 (d) t1>> t2, 4. In an elevator moving vertically up with an, acceleration g, the force exerted on the floor by, a passenger of mass M is, 1, (a) Mg, (b) Mg, (c) Zero, (d) 2Mg, 2, 5. A man weighs 80 kg. He stands on a weighing, scale in a lift which is moving upwards with a, uniform acceleration of 5 m/s2. What would be, the reading on the scale. (g = 10m/s2), (a) 400 N (b) 800 N (c) 1200 N, (d) Zero, 6. Mass of a person sitting in a lift is 50 kg. If lift is, coming down with a constant acceleration of 10, m/sec2. Then the reading of spring balance will, be (g = 10m/sec2), (a) 0 (b) 1000 N, (c) 100 N, (d) 10 N, 7. A man weighing 80kg, stands on a weighing scale, in a lift which is moving upwards with a uniform, acceleration of 5m/s2. What would be the reading on, the scale? (g=10m/s2), (a) 1200N, (b) zero, (c) 400N, (d) 800N, 8. A block of mass m is placed on a smooth wedge of, inclination θ. The whole system is accelerated

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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, (a) mg/cosθ, (b) mg cosθ, (c) mg sinθ (d) mg, 9., A given shaped glass tube having uniform cross, section is filled with water and is mounted on a, rotatable shaft as shown in figure. If the tube is, rotated with a constant angular velocity  then, A, , B, , L, , 2L, , (a) Water levels in both sections A and B go up, (b) Water level in Section A goes up and that in B, comes down, (c) Water level in Section A comes down and that, in B it goes up, (d) Water levels remains same in both sections, , 10. A lift is moving down with acceleration a. A man, in the lift drops a ball inside the lift. The, acceleration of the ball as observed by the man in, the lift and a man standing stationary on the ground, are respectively, (a) g. g, (b) g – a, g – a (c) g – a, g (d) a,, g, 11., A block is kept on a frictionless inclined surface, with angle of inclination ‘α’. The incline is given an, acceleration ‘α’ to keep the block stationary. Then a, is equal to, (a) g cosec α, (b) g / tan α (c) g tan α, (d) g, 12. A jar containing water is placed in a train. The train, accelerates from left to right. Which of the, following shows the water level in jar correctly?, (a), , (b), , (c), , (d), , a, α, , Variable force & Impulse :(Section 4), Variable force, , dv, dv, v, dt, dx, dx, v, dt, 6). a = f (v), a, , m, 1). x = f (t) 2 ). v = f (t) 3). a = f (t), , Fnet, 4). v = f (x), , 5). a = f (x)

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Single Choice Questions, , Impulse, , 6. A player caught a cricket ball of mass 150g moving, at a rate of 20 m/s. If the catching process is, completed in 0.1s, the force of the blow exerted by, the ball on the hand of the player is equal to, (a) 150 N (b) 3 N, (c) 30 N (d) 300 N, , 5. A body of mass 2 kg is hung on a spring balance, mounted vertically in a lift. If the lift descends with, an acceleration equal to the acceleration due to, gravity ‘g’ the reading on the spring balance will, be, (a) 2 kg (b) (4×g) kg (c) (2×g) kg (d) zero, , Force (N), , 1. A light spring balance hangs from the hook of the other, light spring balance and a block of mass M kg hangs, from the former one. Then the true statement about, scale reading is, ], (a) both the scales read M kg each, (b) the scale of the lower one reads M kg and of, upper one zero, (c) the reading of the two scales can be anything, but sum of the reading will be M kg, (d) both the scales read M/2 kg, 2. A particle of mass 0.3 kg subject to a force F = - kx, with k = 15 N/m. What will be its initial acceleration if, it is released from a point 20 cm away from the origin?, (a) 15 m / s2 (b) 3 m / s2 (c) 10 m / s2 (d) 5 m / s2, 3. 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, (a) 24 N, (b) 74 N, (c) 15 N (d) 49 N, 4. A spring of force constant k is cut into two pieces such, that one piece is double the length of the other. Then, the long piece will have a force constant of:, (a) (2/3) k, (b) (3/2) k, (c) 3 k, (d) 6 k, , 7. The engine of a jet aircraft applies a thrust force of, 105 during take off and causes the plane to attain a, velocity of 1 km/sec in 10 sec. The mass of the, plane is, (a) 102 kg (b) 103 kg, (c) 104 kg (d) 105 kg, 8. A ball of mass 0.2 kg moves with a velocity of 20, m/sec and it stops in 0.1 sec; then the force on the, ball is, (a) 40 N, (b) 20 N, (c) 4 N, (d) 2 N, 9. A ball of mass 0.5 kg moving with a velocity of 2, m/sec strikes a wall normally and bounces back, with the same speed. If the time of contact between, the ball and the wall is one millisecond, the, average force exerted by the wall on the ball is, (a) 2000 N (b) 1000 N (c) 5000 N (d) 125 N, 10. A force of 10N acts on a body of mass 20kg for 10, seconds. Change in its momentum is (a) 5kgm/s, (b) 100kgm/s, (c) 200kgm/s, (d) 1000kgm/s, 11. A cricket ball of mass 250 g collides with a bat, with velocity 10 m/s and returns with the same, velocity within 0.10 second. The force acted on bat, is, (a) 25 N, (b) 50 N, (c) 250 N, (d) 500 N, 12. The time in which a force of 2N produces a change, of momentum of 0.4kg-ms-1 in the body, (a) 0.2s, (b) 0.02s, (c) 0.5s, (d) 0.05s, 13. The force–time (F–t) curve of a particle executing, linear motion, is as shown, +2, in the figure., The, 2 4, 6, 8, momentum, Time (s), acquired by, -2, the particle

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in time interval from zero to 8 second will be, (a) –2N-s, (b) +4N-s, (c) 6N-s, (d) Zero, A vehicle of 100 kg is moving with a velocity of 5, 14., m/sec. To stop it in, , 1, sec, the required force in, 10, , opposite direction is, (a) 5000 N (b) 500 N, , (c) 50 N, , (d) 1000 N, , 15. A particle of mass m is moving with a uniform velocity, v1. It is given an impulse such that its velocity becomes, v2. The impulse is equal to, (a) m[|v2|-|v1|] (b) 1/2m[ v22  v12 ], (c) m[v1+v2] (d) m[v2-v1], 16. A body of mass M hits normally a rigid wall with, velocity V and bounces back with the same velocity., The impulse experienced by the body is, (a) MV, (b) 1.5MV (c) 2MV, (d) zero, 17. A bullet is fired from a gun. The force on the bullet is, given by F=600-2×105t where, F is in Newton and t in, second. The force on the bullet becomes zero as soon as, it leaves the barrel. What is the average impulse, imparted to the bullet?], (a) 1.8N-s, (b) zero, (c) 9N-s, (d) 0.9N-s, , Variable mass concept, , 19. n small balls each of mass m impinge elastically, each second on a surface with velocity u. The force, experienced by the surface will be, 1, (a) mnu, (b) 2mnu, (c) 4mnu (d) mnu, 2, 20. A satellite in force-free space sweeps stationary, interplanetary at the rate dM/dt = αv where M is, the mass, v is the velocity of the satellite and α is a, constant. What is the deacceleration of the satellite, (a) –2αv2/M (b) – αv2/M (c) +αv2/M (d) –αv2, 21. A diwali rocket is ejecting 0.05 kg of gases per sec., at a velocity of 400 m/s. The acceleration force on, the rocket is, (a) 20 dynes (b) 20 N (c) 22 dynes (d) 1000 N, 22. In a rocket of mass 1000 kg fuel is consumed at a, rate of 40 kg/s. The velocity of the gases ejected, from the rocket is 5×104 m/s. The thrust on the, rocket is, (a) 2×103N (b) 5×104 N (c) 2×106N (d) 2×109N, 23. A train is moving with velocity 20 m/sec. on this, dust is falling at the rate of 50 kg/minute. The extra, force required to move this train with constant, velocity will be, (a) 16.66 N (b) 1000 N (c) 166.6 N (d) 1200 N, 24. The average resisting force that must act on a 5 kg, mass to reduce its speed from 65 cm/s to 15 cm/s, in 0.2s is, (a) 12.5 N (b) 25 N (c) 50 N (d) 100 N, 25. A rocket is ejecting 50g of gases per sec at a speed, of 500m/s. The acceleration force on the rocket, will be, (a) 125N, (b) 25N, (c) 5N, (d) Zero, 26. A 6kg rocket is set for a vertical firing. If the exhaust, speed is 1000ms-1, the mass of the gas ejected per, second to supply the trust needed to overcome the, weight of rocket is, (a) 117.6kgs-1 (b) 58.6kgs-1 (c) 0.06kgs-1 (d) 76.4kgs-1, 27. A 5000 kg rocket is set for vertical firing. The exhaust, speed is 800ms-1. To give an initial upward acceleration, of 20ms-2, the amount of gas ejected per second to, supply the needed thrust will be (g=10ms-2), , 18. A gun of mass 10kg fires 4 bullets per second. The, mass of each bullet is 20g and the velocity of the, (a) 127.5kgs-1, (b) 187.5kgs-1, -1, -1, bullet when it leaves the gun is 300ms . The force, (c)185.5kgs, (d) 137.5kgs-1, required to hold the gun while firing is, 28. Sand is being dropped on a conveyor belt at the rate of, (a) 6N, (b) 8N, (c) 24N, (d) 240N, M kg/s. The force necessary to keep the belt moving, with a constant velocity of v m/s will be:, [CBSE 2008]