JEE Questions for Physics Work Energy And Power Quiz 8 - MCQExams.com

A particle is moving under the influence of a force given by F = kx, where k is a constant and x is the distance moved. The energy (in joules) gained by the particle in moving from x = 0 to x = 3 is
  • 2.5 k
  • 3.5 k
  • 4.5 k
  • 9 k
  • 9.5 k
A wire is stretched under a force. If the wire suddenly snaps the temperature of the wire
  • Remains the same
  • Decreases
  • Increases
  • First decreases then increases
A position dependent force F =7 – 2x + 3x2 N acts on a small body of mass 2 kg and displaces it from x = 0 to x = 5 m. The work done in joules is
  • 70
  • 270
  • 35
  • 135
When a 1.0 kg mass hangs attached to a spring of length 50 cm, the spring stretches by 2 cm. The mass is pulled down until the length of the spring becomes 60 cm. What is the amount of elastic energy stored in the spring in this condition, if g l0 m/s2?
  • 1.5 J
  • 2.0 J
  • 2.5 J
  • 3.0 J
A spring of force constant 800 N/m has an extension of 5 cm. The work done in extending it from 5 cm to 15 cm is
  • 16 J
  • 8 J
  • 32 J
  • 24 J
When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by
  • 100 J
  • 200 J
  • 300 J
  • 400 J
A spring when stretched by 2 mm its potential energy becomes 4 J. If it is stretched by 10 mm, its potential energy is equal to
  • 4 J
  • 54 J
  • 415 J
  • None of these

Physics-Work Energy and Power-97876.png
  • 6.25 N-m
  • 12.50 N-m
  • 18.75 N-m
  • 25.00 N-m
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to

  • Physics-Work Energy and Power-97878.png
  • 2)
    Physics-Work Energy and Power-97879.png

  • Physics-Work Energy and Power-97880.png

  • Physics-Work Energy and Power-97881.png
Natural length of a spring is 60 cm, and its spring constant is 4000 N/m. A mass of 20 kg is hung from it. The extension produced in the spring is, (Take g = 9.8 m/s2)
  • 4.9 cm
  • 0.49 cm
  • 9.4 cm
  • 0.94 cm
The potential energy of a body is given by, U = A – Bx2 (where x is the displacement). The magnitude of force acting on the particle is
  • Constant
  • Proportional to x
  • Proportional to x2
  • Inversely proportional to x

Physics-Work Energy and Power-97885.png

  • Physics-Work Energy and Power-97886.png
  • 2)
    Physics-Work Energy and Power-97887.png

  • Physics-Work Energy and Power-97888.png

  • Physics-Work Energy and Power-97889.png
A rod AB of mass 10 kg and length 4 m rests on a horizontal floor with end A fixed so as to rotate it in vertical plane about perpendicular axis passing through A. If the work done on the rod is 100 J, the height to which the end B be raised vertically above the floor is
  • 1.5 m
  • 2.0 m
  • 1.0 m
  • 2.5 m
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
  • 7.2 J
  • 3.6 J
  • 120 J
  • 1200 J
Two bodies of masses m1 and m2 have equal kinetic energies. If p1 and p2 are their respective momentum, then ratio p1 : p2 is equal to

  • Physics-Work Energy and Power-97893.png
  • 2)
    Physics-Work Energy and Power-97894.png

  • Physics-Work Energy and Power-97895.png

  • Physics-Work Energy and Power-97896.png
The kinetic energy possessed by a body of mass m moving with a velocity V is equal to 1/2 mv2 provided
  • The body moves with velocities comparable to that of light
  • The body moves with velocities negligible compared to the speed of light
  • The body moves with velocities greater than that of light
  • None of the above statement is correct

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  • Physics-Work Energy and Power-97899.png
  • 2

  • Physics-Work Energy and Power-97900.png

  • Physics-Work Energy and Power-97901.png

  • Physics-Work Energy and Power-97902.png
The bob of a simple pendulum (mass m and length l) dropped 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
A spring gun of spring constant 90 N/cm is compressed 12 cm by a ball of mass 16 g. If the trigger is pulled, the velocity of the ball is
  • 50 ms–1
  • 9 ms–1
  • 40 ms–1
  • 60 ms–1
  • 90 ms–1
A bullet of mass 0.05 kg moving with a speed of 80 ms–1 enters a wooden block and is stopped after a distance of 0.40 m. The average resistive force exerted by the block on the bullet is
  • 300 N
  • 20 N
  • 400 N
  • 40 N
  • 200 N
An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the rang

  • Physics-Work Energy and Power-97907.png
  • 2)
    Physics-Work Energy and Power-97908.png

  • Physics-Work Energy and Power-97909.png

  • Physics-Work Energy and Power-97910.png
In an explosion a body breaks up into two pieces of unequal masses. In this
  • Both parts will have numerically equal momentum
  • Lighter part will have more momentum
  • Heavier part will have more momentum
  • Both parts will have equal kinetic energy
The block of mass M moving on the frictionless horizontal surface collides with the spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is
Physics-Work Energy and Power-97912.png
  • zero
  • 2)
    Physics-Work Energy and Power-97913.png

  • Physics-Work Energy and Power-97914.png

  • Physics-Work Energy and Power-97915.png
A particle of mass m moving with velocity Vo strikes a simple pendulum of mass m and sticks to it. The maximum height attained by the pendulum will be

  • Physics-Work Energy and Power-97917.png
  • 2)
    Physics-Work Energy and Power-97918.png

  • Physics-Work Energy and Power-97919.png

  • Physics-Work Energy and Power-97920.png
If a shell fired from a cannon, explodes in mid air, then
  • Its total kinetic energy increases
  • Its total momentum increases
  • Its total momentum decreases
  • None of the above
A body is moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then, the velocity of the other part is
  • v in forward direction
  • 3v in forward direction
  • v in backward direction
  • 3v in backward direction
Two trolleys of mass m and 3 m are connected by a spring. They were compressed and released once, they move off in opposite direction and comes to rest after covering distances S1 and S2 respectively. Assuming the coefficient of friction to be uniform, the ratio of distances S1 : S2 is
  • 1 : 9
  • 1 : 3
  • 3 : 1
  • 9 : 1
In which case does the potential energy decrease?
  • On compressing a spring
  • On stretching a spring
  • On moving a body against gravitational force
  • On the rising of an air bubble in water
A sphere of mass in, moving with velocity V, enters a hanging bag of sand and stops. If the mass of the hag is M and it is raised by height h, then the velocity of the sphere was

  • Physics-Work Energy and Power-97924.png
  • 2)
    Physics-Work Energy and Power-97925.png

  • Physics-Work Energy and Power-97926.png

  • Physics-Work Energy and Power-97927.png
Two bodies of masses m and 2m have same momentum. Their respective kinetic energies E1 and E2 are in the ratio
  • 1 : 2
  • 2 : 1

  • Physics-Work Energy and Power-97929.png
  • 1 : 4
If a lighter body (mass M1 and velocity V1) and a heavier body (mass M2 and velocity V2) have the same kinetic energy, then

  • Physics-Work Energy and Power-97931.png
  • 2)
    Physics-Work Energy and Power-97932.png

  • Physics-Work Energy and Power-97933.png

  • Physics-Work Energy and Power-97934.png
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
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
Two bodies of masses 2 m and m have their K.E. in the ratio 8 : 1, then their ratio of momenta is
  • 1 : 1
  • 2 : 1
  • 4 : 1
  • 8 : 1
A bomb of 12 kg divides in two parts whose ratio of masses is 1: 3. If kinetic energy of smaller part is 216 J, then momentum of bigger part in kg-m/sec will be
  • 36
  • 72
  • 108
  • Data is incomplete
A body at rest breaks into two pieces with unequal mass
  • Both of them have equal speeds
  • Both of them move along a same line with unequal speed
  • Sum of their momentum is non-zero
  • They move along different lines with different speeds.
A particle is released from a height S. At certain height its kinetic energy is three times its potential energy. The height and speed of the particle at that instant are respectively

  • Physics-Work Energy and Power-97940.png
  • 2)
    Physics-Work Energy and Power-97941.png

  • Physics-Work Energy and Power-97942.png

  • Physics-Work Energy and Power-97943.png
Which among the following is a form of energy?
  • Light
  • Pressure
  • Momentum
  • Power
If a body of mass 200 g falls from a height 200 m and its total P.E. is converted into K.E. at the point of contact of the body with Earth surface, then what is the decrease in P.E. of the body at the contact? (g = 10 m/s2)
  • 200 J
  • 400 J
  • 600 J
  • 900 J
A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1g and 3g. The total K.E. of the fragments is 6.4 x 104 J. What is the K.E. of the smaller fragment?

  • Physics-Work Energy and Power-97946.png
  • 2)
    Physics-Work Energy and Power-97947.png

  • Physics-Work Energy and Power-97948.png

  • Physics-Work Energy and Power-97949.png

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  • Physics-Work Energy and Power-97952.png
  • 2)
    Physics-Work Energy and Power-97953.png

  • Physics-Work Energy and Power-97954.png

  • Physics-Work Energy and Power-97955.png
The decrease in the potential energy of a ball of mass 20 kg which falls from a height of 50 cm is
  • 968 J
  • 98 J
  • 1980 J
  • None of these
If a man increase his speed by 2 m/s, his K.E. is doubled, the original speed of the man is

  • Physics-Work Energy and Power-97958.png
  • 2)
    Physics-Work Energy and Power-97959.png

  • Physics-Work Energy and Power-97960.png

  • Physics-Work Energy and Power-97961.png
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 g = 9.8 m/s2)
Physics-Work Energy and Power-97963.png
  • 0.6 m/s
  • 1.4 m/s
  • 1.8 m/s
  • 2.2 m/s
A particle of mass ‘m’ and charge ‘q’ is accelerated through a potential difference of ‘V volt, its energy is

  • Physics-Work Energy and Power-97965.png
  • 2)
    Physics-Work Energy and Power-97966.png

  • Physics-Work Energy and Power-97967.png

  • Physics-Work Energy and Power-97968.png
If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest?
  • 1 cm
  • 2 cm
  • 3 cm
  • 4 cm
Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into
  • Heat energy
  • Electrical energy
  • Nuclear energy
  • Mechanical energy
A particle of mass m at rest is acted upon by a force F for a time t. Its kinetic energy after an interval t is

  • Physics-Work Energy and Power-97970.png
  • 2)
    Physics-Work Energy and Power-97971.png

  • Physics-Work Energy and Power-97972.png

  • Physics-Work Energy and Power-97973.png
The potential energy of a weight less spring compressed by a distance a is proportional to
  • a
  • a2
  • a–2
  • ao
A simple pendulum is released from A as shown. If m and l represent the mass of the bob and length of the pendulum, the gain in kinetic energy at B is
Physics-Work Energy and Power-97976.png

  • Physics-Work Energy and Power-97977.png
  • 2)
    Physics-Work Energy and Power-97978.png

  • Physics-Work Energy and Power-97979.png

  • Physics-Work Energy and Power-97980.png
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