Q.1
In Q 269 the impulse acting on the object is
  • a) 120 N × s
  • b) -120 N × s
  • c)30 N× s
  • d)-30 N× s
Q.2
A ball impinges directly on another ball at rest and is brought to rest by impact. If half of the initial kinetic energy is lost in the impact, the coefficient of restitution is
  • a) 1/3
  • b) 1/2
  • c) 2/3
  • d) 1/4
Q.3
In Q 273 acceleration of car will be
  • a) 0.25 m/s²
  • b) 2.5 m/s²
  • c)5.0 m/s²
  • d)0.025 m/s²
Q.4
To solid rubber balls A and B, having masses 200 and 400 gm respectively, are moving in opposite directions with velocity of A equal to 0.3m/s. After collision, the combination of two balls comes to rest when velocity of B is
  • a) 0.15 m/s
  • b) 1.5 m/s
  • c)-0.15 m/s
  • d)none of the above
Q.5
A balloon has 2g air. A small hole is pierced into it. The air forces out with a velocity 4m/s. If the balloon shrinks completely in 2.5 s the average force acting on the balloon is
  • a)0.008 N
  • b) 8 N
  • c)0.0032 N
  • d)3.2 N
Q.6
The force required to just move up the inclined plane is doubled the force equal to just prevent the body from sliding down the plane. The coefficient of friction is µ. The inclination θ of the plane is
  • a) tan-1µ
  • b) tan⁻¹(µ/2)
  • c)tan-12µ
  • d)tan-13µ
Q.7
A massless string of length l passes over a frictionless pulley whose axis is horizontal. Two monkeys hang from the end of the string at the same distance l/2 from the pulley, the monkeys start climbing upwards simultaneously. First monkey climbs with a speed v relative to the string and the second with speed 2v. Both monkeys have equal masses. Then the times taken by the first and second monkey in meeting each other are respectively
  • a) l/v and l/2v
  • b) l/2v and l/4v
  • c)l/4v and l/2v
  • d)l/3v and l/3v
Q.8
A body of mass m collides against a wall witha velocity v and rebounds with the same velocity. The change in momentum of the wall is
  • a) zero
  • b) mv
  • c) -2mv
  • d) -mv
Q.9
When a bullet of mass 5gm is fired, the impulse on the it is 200N. IF the mass of the gun is 10kg, then the recoil velocity of the gun is:
  • a)20 m/s
  • b) 0.2 m/s
  • c)2 m/s
  • d)0.02 m/s
Q.10
A body acted upon a force F has an acceleration "A" . When it is acted upon by two forces each of magnitude F at right angles to each other, its acceleration will be
  • a) 2A
  • b) A
  • c)A√2
  • d)√2
Q.11
Pulling is easier than pushing because
  • a) When we pull a roller, the vertical component of the pulling force acts in the direction of weight
  • b) the vertical component of the pulling force acts in the opposite direction of weight
  • c)of force of friction is in opposite direction
  • d)it is possible in the case of roller only
Q.12
A jet of water with cross-sectional area 'a' is striking against a wall at an angle θ to the horizontal and rebound elastically. IF the velocity of water jet is 'v' and the density is ρ, the normal force acting on the wall is
  • a) 2av2ρcosθ
  • b) av2ρcosθ
  • c) 2av ρcosθ
  • d) av cosθ
Q.13
A rope of length L and mass M is hanging from a rigid support. The tension in the rope at a distance x from rigid support is
  • a)Mg
  • b) [(L-x)/L]Mg
  • c)[L/(L-x)]Mg
  • d)xMg/L
Q.14
In which of the following cases forces may not be required to keep the
  • a) particle going in a circle
  • b) particle going along a straight line
  • c)the momentum of the particle constant
  • d)acceleration of the particle constant
Q.15
In case of a block lying on the table
  • a) action of the block on the table and reaction of table on the block are equal and opposite and are inclined to the vertical
  • b) action and reaction are equal and opposite and act perpendicular to the surfaces of contact.
  • c)action and reaction are equal but act in the same direction
  • d)action and reaction are not equal but are in opposite direction
Q.16
While dusting a carpet we give a sudden jerk or beat it with a stick because
  • a) inertia of rest keeps the dust in its position and dirt is removed by the movement of carpet
  • b) inertial of motion removes the dirt
  • c) practical experience sujjest that the jerks are necessary for the removal of dirt
  • d) none of above
Q.17
When a body is stationary
  • a)there is no force acting on it
  • b) the force acting on it is not in contact with it
  • c)the combination of force acting on it balances each other
  • d)the body is in vacuum
Q.18
Which of the following statemenmt is correct. when a person walks on the rough surface
  • a) the frictional force exerted by the surface keeps him moving
  • b) the force which the man exerts on the floor keeps him moving
  • c)the reaction of the force which the man exerts on floor keeps him moving
  • d)none of the above
Q.19
The law of conservation of linear momentum is a logical consequence of Newton's
  • a) first law
  • b) second law
  • c)third law
  • d)all the three laws
Q.20
Mr A of mass 80 kg enters a lift and seclects the floor he wants. the lift now accelerateds up at 1 m/s2 for seconds and then moves with constant spped. As the lift approaches his floor it deaccelerated at the same rate as itt was accelerate. If the lift can withstand a tension of 2×104N, the lift itself has a mass of 500kg, how many Mr.A's can it carry at one time
  • a) 22
  • b) 16
  • c) 18
  • d) 12
Q.21
A massless string of length l passes over a frictionless pulley whose axis is horizontal. Two monkey hang from the ends of the string at the same distance (l/2) from the pulley, the monkey starts climbing upwards simultaneously. The first monkey climbs upwards with an acceleration 'a' and the second with an acceleration 2a relative to the rope, then the times taken by the first and second monkey in meeting each other are respectively
  • a)
    ch-4_qn-297choice_img_no1.png
  • b)
    ch-4_qn-297choice_img_no2.png
  • c)
    ch-4_qn-297choice_img_no3.png
  • d)
    ch-4_qn-297choice_img_no4.png
Q.22
The average force that is necessary to stop a hammer with 25 newton-sec momentum in 0.05 sec, expressed in newtons is
  • a) 500
  • b) 125
  • c)50
  • d)25
Q.23
A given object takes n times as much time to slide down a 45o rough inclined as it takes to slide down a perfectly smooth 45o incline. The coefficient of kinetic friction between the object and incline is given by
  • a)
    ch-4_qn-299choice_img_no1.png
  • b)
    ch-4_qn-299choice_img_no2.png
  • c)
    ch-4_qn-299choice_img_no3.png
  • d)
    ch-4_qn-299choice_img_no4.png
Q.24
A body of mass 2 kg moving with a velocity of 3m/sec collides head on with a body of mass 1kg moving in opposite direction with velocity of 4m/s. After collision, two bodies stick together and move with a common velocity which, in the units of m/s, is equal to
  • a) 1/4
  • b) 1/3
  • c) 2/3
  • d) 2/4
Q.25
A 15 kg mass is accelerated from rest with a force of 100N. AS it moves faster, friction and air resistance create an oppositely directed retarding force given by FR=A + BV Where A=25 N and B=0.5N-s/m. At what velocity does the acceleration is one half the initial acceleration [ Manipal PMT 1996]
  • a)25 m/s
  • b) 50 m/s
  • c)75 m/s
  • d)100 m/s
Q.26
Which of the following statement about friction is true?
  • a) friction can be reduced to zero
  • b) frictional force an accelerate a body
  • c)frictional force is proportional to the area of contact between the two surfaces
  • d)kinetic friction is always greater than rolling friction
Q.27
A force of 1N acts upon a mass of 1kg for 1 second and gives it a momentum P and kinetic energy E. The same force acts upon the same mass for displacement of 1m and gives it a momentum P' and kinetic energy E'. Then
  • a) P=P' , E=E'
  • b)P > P' , E > E'
  • c)P < P' , E < E'
  • d)P > P' , E < E'
Q.28
A 40 kg slab rests on frictionless floor as shown in figure. A 10kg block rests on the top of a slab. The static coefficient of friction between the block and slab is 0.6 while the kinetic friction is 0.The 10kg blcok is acted upon by a horizontal force of 100N. If g=9.8 m/s2, the resultant acceleration of the slab will be
ch-4_que_no-304_img_no1.png
  • a) 0.98 m/s²
  • b) 1.47 m/s²
  • c) 1.52 m/s²
  • d) 6.1 m/s²
Q.29
When a bus suddenly takes a turn, the passengers are thrown outwards because of . [AFMC 1999; CPMT]
  • a) Inertia of motion
  • b) Speed of motion
  • c) Acceleration of motion
  • d) Both (b) and (c)
Q.30
To avoid slipping while walking on ice, one should take smaller steps because of the. [BHU 1999; BCECE]
  • a)Friction of ice is large
  • b) Friction of ice is small
  • c)Larger normal reaction
  • d)Smaller normal reaction
0 h : 0 m : 1 s