JEE Questions for Physics Work Energy And Power Quiz 5 - MCQExams.com


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  • 9.5 W
  • 7.5 W
  • 6.5 W
  • 4.5 W
A light and a heavy body have equal momenta. Which one has greater K.E
  • The light body
  • The heavy body
  • The K.E are equal
  • Data is incomplete
The bob of a simple pendulum (mass m and lengthdropped from a horizontal position strikes a block of the same mass elastically placed on a horizontal frictionless table. The K.E. of the block will be
  • 2 mgl
  • mgl/2
  • mgl
  • 0
According to work-energy theorem, the work done by the net force on a particle is equal to the change in its
  • Kinetic energy
  • Potential energy
  • Linear momentum
  • Angular momentum
  • Acceleration
Two masses of 1g and 4g are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is
  • 4 : 1
  • 2)
    Physics-Work Energy and Power-97646.png
  • 1 : 2
  • 1 : 16
If the K.E of a body is increased by 300%, its momentum will increase by
  • 100%
  • 1560%

  • Physics-Work Energy and Power-97648.png
  • 175%
If the K.E. of a particle is doubled, then its momentum will
  • Remain unchanged
  • Be doubled
  • Be quadrupled
  • Increase √2 times
If the kinetic energy of a body increases by 0.1%, the percent increase of its momentum will be
  • 0.05%
  • 0.1%
  • 1.0%
  • 10%
If velocity of a body is twice of previous velocity, the kinetic energy will become
  • 2 times
  • 1/2 times
  • 4 times
  • 1 times
Two bodies with kinetic energies in the ratio of 4 : 1 are moving with equal linear momentum. The ratio of their masses is
  • 1 : 2
  • 1 : 1
  • 4 : 1
  • 1 : 4
A bullet is fired from a rifle. If the rifle recoils freely, then the kinetic energy of the rifle is
  • Less than that of the bullet
  • More than that of the bullet
  • Same as that of the bullet
  • Equal or less than that of the bullet
If the water falls from a dam into a turbine wheel 19.6 m below, then the velocity of water at the turbine is (g = 9.8 m/s2)
  • 9.8 m/s
  • 19.6 m/s
  • 39.2 m/s
  • 98.0 m/s
The decrease in the potential energy of a ball of mass 20 kg which falls from a height of 50 cm is
  • 968 J
  • 898 J
  • 1980 J
  • None of these
A 0.5 kg ball is thrown up with an initial up with an initial speed 14 m/s and reaches a maximum height of 8.0 m. How much energy is dissipated by air drag acting on the ball during the ascent
  • 19.6 Joule
  • 4.9 Joule
  • 10 Joule
  • 9.8 Joule
What is the velocity of the bob of a simple pendulum at its mean position, if it is able to rise to vertical height of 10 cm. (Take = 9.8 m/s2)
Physics-Work Energy and Power-97658.png
  • 0.6 m/s
  • 1.4 m/s
  • 1.8 m/s
  • 2.2 m/s
A machine which is 75 percent efficient, uses 12 joules of energy in lifting up a 1 kg mass through a certain distance. The mass is then allowed to fall through that distance. The velocity at the end of its fall is (in m/s-1)

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  • 2)
    Physics-Work Energy and Power-97664.png

  • Physics-Work Energy and Power-97665.png

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The kinetic energy of a body of mass 3 Kg and momentum 2 Ns is
  • 1 J
  • 2)
    Physics-Work Energy and Power-97668.png

  • Physics-Work Energy and Power-97669.png
  • 4J
A ball of mass 2 kg and another of mass 4kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

  • Physics-Work Energy and Power-97671.png
  • 1 : 4
  • 1 : 2

  • Physics-Work Energy and Power-97672.png
The coefficient of restitution e for a perfectly elastic collision is
  • 1
  • 0
  • ∞
  • –1
Two solid rubber balls A and B having masses 200 and 400 g respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is
  • 0.15 m/sec
  • 1.5 m/sec
  • –0.15 m/sec
  • None of the above
A body of mass `M\' collides against a wall with a velocity v and retraces its path with the same speed. The change in momentum is (take initial direction of velocity as positive)
  • zero
  • 2Mv
  • Mv
  • –2Mv
In an elastic collision of two particles the following is conserved
  • Momentum of each particle
  • Speed of each particle
  • Kinetic energy of each particle
  • Total kinetic energy of both the particles
A body falling from a height of 10 m rebounds from hard floor. If it loses 20% energy in the impact, then coefficient of restitution is
  • 0.89
  • 0.56
  • 0.23
  • 0.18
A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is
  • 16/81
  • 8/9
  • 8/27
  • 2/3
A uniform chain of length L and mass M is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, the work required to pull the hanging part on to the table is
  • MgL
  • MgL/3
  • MgL/9
  • MgL/18
A lorry and a car moving with the same K.E. are brought to rest by applying the same retarding force, then
  • Lorry will come to rest in a shorter distance
  • Car will come to rest in a shorter distance
  • Both come to rest in a same distance
  • None of the above
The kinetic energy acquired by a mass m in travelling a certain distance d starting from rest under the action of a constant force is directly proportional to

  • Physics-Work Energy and Power-97680.png
  • Independent of m

  • Physics-Work Energy and Power-97681.png
  • m
A body is moved along a stright line by a machine delivering constant power. The distance moved by the body in time t is proportional to
  • t1/2
  • t3/4
  • t3/2
  • t2
A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explosion that generates 1.05 kJ or energy. The initial velocity of the shell is
  • 40 ms–1
  • 120 ms–1
  • 100 ms–1
  • 80 ms–1
The coefficient of restitution e for a perfectly inelastic collision is
  • 1
  • 0
  • ∞
  • –1
A 50 g bullet moving with velocity 10 m/s strikes a block of mass 950 g at rest and gets embedded in it. The loss in kinetic energy will be
  • 100%
  • 95 %
  • 5%
  • 50%
A particle of mass m moving with velocity v striles a stationary particle of mass 2m and sticks to it. The speed of the system will be
  • v/2
  • 2v
  • v/3
  • 3v
In an inelastic collision, what is conserved
  • Kinetic energy
  • Momentum
  • Both (and (2)
  • Neither (and (2)
A body of mass 2 kg is moving with velocity 10 m/s towards east. Another body of same mass and same velocity moving towards north collides with former and coalesces and moves towards north-east. Its velocity is
  • 10 m/s
  • 5 m/s
  • 2.5 m/s
  • 5√2 m/s
Which of the following is not a perfectly inelastic collision
  • Striking of two glass balls
  • A bullet striking a bag of sand
  • An electron captured by a proton
  • A man jumping onto a moving cart
The quantity that is not conserved in an inelastic collision is
  • Momentum
  • Kinetic energy
  • Total energy
  • All of these
A ball moves in a frictionless inclined table without slipping. The work done by the table surface on the ball is
  • Positive
  • Negative
  • Zero
  • None of these
A horizontal force of 5 N is required to maintain a velocity of 2 m/s for a block of 10 kg mass sliding over a rough surface. The work done by this force in one minute is
  • 600 J
  • 60 J
  • 6 J
  • 6000 J
Identify the wrong statement
  • A body can have momentum without energy
  • A body can have energy without momentum
  • The momentum is conserved in an elastic collision
  • Kinetic energy is not conserved in an inelastic collision
A nucleus at rest splits into two nuclear parts having same density and radii in the ratio 1 : 2. Their velocities are in the ratio
  • 2 : 1
  • 4 : 1
  • 6 : 1
  • 8 : 1
The slope of kinetic energy displacement curve of a particle in motion is
  • Equal to the acceleration of the particle
  • Inversely proportional to the acceleration
  • Directly proportional to the acceleration
  • None of the above
The energy required to accelerate a car from 10 m/s to 20 m/s is how many times the energy required to accelerate the car from rest to 10 m/s
  • Equal
  • 4 times
  • 2 times
  • 3 times

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  • 1
  • 3
  • 4
  • 5

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  • Physics-Work Energy and Power-97694.png
  • 2)
    Physics-Work Energy and Power-97695.png

  • Physics-Work Energy and Power-97696.png

  • Physics-Work Energy and Power-97697.png
A block C of mass m is moving with velocity vo and collides elastically with block A of mass m and connected to another block B of mass 2m through spring constant k. What is k, if xo is compression of spring when velocity of A and B is same ?
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  • Physics-Work Energy and Power-97700.png
  • 2)
    Physics-Work Energy and Power-97701.png

  • Physics-Work Energy and Power-97702.png

  • Physics-Work Energy and Power-97703.png
Consider the following statements A and B and identify the correct answer.
A. In an elastic collision, if a body suffers a head on collision with another of same mass at rest, the first body comes to rest while the other starts moving with the velocity of the first one.
B. Two bodies of equal mass suffering a head on elastic collision merely exchanges their velocities.
  • Both Statement A and Statement B are correct
  • Both Statement A and Statement B are incrorect
  • Statement A is correct and Statement B is incorrect
  • Statement A is incorrect but Statement B is correct

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  • 2)
    Physics-Work Energy and Power-97707.png

  • Physics-Work Energy and Power-97708.png

  • Physics-Work Energy and Power-97709.png
A vertical spring with force constant k is fixed on a table. A ball of mass mat a height h above the free upper end of the spring falls vertically on the spring, so that the spring is compressed by a distance d. The net work done in the process is

  • Physics-Work Energy and Power-97711.png
  • 2)
    Physics-Work Energy and Power-97712.png

  • Physics-Work Energy and Power-97713.png

  • Physics-Work Energy and Power-97714.png
A spring of natural length AB is extended upto C. if spring constant is k, then energy stored is
Physics-Work Energy and Power-97716.png

  • Physics-Work Energy and Power-97717.png
  • 2)
    Physics-Work Energy and Power-97718.png

  • Physics-Work Energy and Power-97719.png

  • Physics-Work Energy and Power-97720.png
A lorry and a car moving with the same kinetic energy are brought to rest by the application of brakes which provide equal retarding forces. Which of them will come to rest in a shorter distance ?
  • the lorry
  • the car
  • both will travel the same distance before coming to rest
  • the distance of travel will depend upon the horsepower of the vehicles
0:0:1


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