Chapter 6: Work And Energy

82 Questions | Total Attempts: 299

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Energy Quizzes & Trivia

Questions and Answers
  • 1. 
    What is the correct unit of work expressed in SI units?
    • A. 

      Kg m/s^2

    • B. 

      Kg m^2/s

    • C. 

      Kg m^2/s^2

    • D. 

      Kg^2 m/s^2

  • 2. 
    Can work be done on a system if there is no motion?
    • A. 

      Yes, if an outside force is provided.

    • B. 

      Yes, since motion is only relative.

    • C. 

      No, since a system which is not moving has no energy.

    • D. 

      No, because of the way work is defined.

  • 3. 
    If you push twice as hard against a stationary brick wall, the amount of work you do
    • A. 

      Doubles.

    • B. 

      Is cut in half.

    • C. 

      Remains constant but non-zero.

    • D. 

      Remains constant at zero.

  • 4. 
    A 50-N object was lifted 2.0 m vertically and is being held there. How much work is being done in holding the box in this position?
    • A. 

      More than 100 J

    • B. 

      100 J

    • C. 

      Less than 100 J, but more than 0 J

    • D. 

      0 J

  • 5. 
    If you walk 5.0 m horizontally forward at a constant velocity carrying a 10-N object, the amount of work you do is
    • A. 

      More than 50 J.

    • B. 

      Equal to 50 J.

    • C. 

      Less than 50 J, but more than 0 J.

    • D. 

      Zero.

  • 6. 
    A container of water is lifted vertically 3.0 m then returned to its original position. If the total weight is 30 N, how much work was done?
    • A. 

      45 J

    • B. 

      90 J

    • C. 

      180 J

    • D. 

      No work was done.

  • 7. 
    Does the centripetal force acting on an object do work on the object?
    • A. 

      Yes, since a force acts and the object moves, and work is force times distance.

    • B. 

      Yes, since it takes energy to turn an object.

    • C. 

      No, because the object has constant speed.

    • D. 

      No, because the force and the displacement of the object are perpendicular.

  • 8. 
    You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.
    • A. 

      Work is + on the way up and + on the way down.

    • B. 

      Work is + on the way up and - on the way down.

    • C. 

      Work is - on the way up and + on the way down.

    • D. 

      Work is - on the way up and - on the way down.

  • 9. 
    The area under the curve, on a Force versus position (F vs. x) graph, represents
    • A. 

      Work.

    • B. 

      Kinetic energy.

    • C. 

      Power.

    • D. 

      Potential energy.

  • 10. 
    On a plot of Force versus position (F vs. x), what represents the work done by the force F?
    • A. 

      The slope of the curve

    • B. 

      The length of the curve

    • C. 

      The area under the curve

    • D. 

      The product of the maximum force times the maximum x

  • 11. 
    The quantity 1/2 mv^2 is
    • A. 

      The kinetic energy of the object.

    • B. 

      The potential energy of the object.

    • C. 

      The work done on the object by the force.

    • D. 

      The power supplied to the object by the force.

  • 12. 
    If the net work done on an object is positive, then the object's kinetic energy
    • A. 

      Decreases.

    • B. 

      Remains the same.

    • C. 

      Increases.

    • D. 

      Is zero.

  • 13. 
    If the net work done on an object is negative, then the object's kinetic energy
    • A. 

      Decreases.

    • B. 

      Remains the same.

    • C. 

      Increases.

    • D. 

      Is zero.

  • 14. 
    If the net work done on an object is zero, then the object's kinetic energy
    • A. 

      Decreases.

    • B. 

      Remains the same.

    • C. 

      Increases.

    • D. 

      Is zero.

  • 15. 
    A truck weighs twice as much as a car, and is moving at twice the speed of the car. Which statement is true about the truck's kinetic energy compared to that of the car?
    • A. 

      All that can be said is that the truck has more kinetic energy.

    • B. 

      The truck has twice the kinetic energy of the car.

    • C. 

      The truck has 4 times the kinetic energy of the car.

    • D. 

      The truck has 8 times the kinetic energy of the car.

  • 16. 
    Car J moves twice as fast as car K, and car J has half the mass of car K. The kinetic energy of car J, compared to car K is
    • A. 

      The same.

    • B. 

      2 to 1.

    • C. 

      4 to 1.

    • D. 

      1 to 2.

  • 17. 
    An object hits a wall and bounces back with half of its original speed. What is the ratio of the final kinetic energy to the initial kinetic energy?
    • A. 

      1/2

    • B. 

      1/4

    • C. 

      2

    • D. 

      4

  • 18. 
    A brick is moving at a speed of 3 m/s and a pebble is moving at a speed of 5 m/s. If both objects have the same kinetic energy, what is the ratio of the brick's mass to the rock's mass?
    • A. 

      25 to 9

    • B. 

      5 to 3

    • C. 

      12.5 to 4.5

    • D. 

      3 to 5

  • 19. 
    A 4.0-kg mass is moving with speed 2.0 m/s. A 1.0-kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant braking force, and are brought to rest. Which object travels the greater distance before stopping?
    • A. 

      The 4.0-kg mass

    • B. 

      The 1.0-kg mass

    • C. 

      Both travel the same distance.

    • D. 

      Cannot be determined from the information given

  • 20. 
    You slam on the brakes of your car in a panic, and skid a certain distance on a straight, level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?
    • A. 

      It would have skidded 4 times farther.

    • B. 

      It would have skidded twice as far.

    • C. 

      It would have skidded 1.4 times farther.

    • D. 

      It is impossible to tell from the information given.

  • 21. 
    A planet of constant mass orbits the Sun in an elliptical orbit. Neglecting any friction effects, what happens to the planet's kinetic energy?
    • A. 

      It remains constant.

    • B. 

      It increases continually.

    • C. 

      It decreases continually.

    • D. 

      It increases when the planet approaches the Sun, and decreases when it moves farther away.

  • 22. 
    The quantity mgy is
    • A. 

      The kinetic energy of the object.

    • B. 

      The gravitational potential energy of the object.

    • C. 

      The work done on the object by the force.

    • D. 

      The power supplied to the object by the force.

  • 23. 
    The quantity 1/2 kx^2 is
    • A. 

      The kinetic energy of the object.

    • B. 

      The elastic potential energy of the object.

    • C. 

      The work done on the object by the force.

    • D. 

      The power supplied to the object by the force.

  • 24. 
    Is it possible for a system to have negative potential energy?
    • A. 

      Yes, as long as the total energy is positive.

    • B. 

      Yes, since the choice of the zero of potential energy is arbitrary.

    • C. 

      No, because the kinetic energy of a system must equal its potential energy.

    • D. 

      No, because this would have no physical meaning.

  • 25. 
    An object is released from rest a height h above the ground. A second object with four times the mass of the first if released from the same height. The potential energy of the second object compared to the first is
    • A. 

      One-fourth as much.

    • B. 

      One-half as much.

    • C. 

      Twice as much.

    • D. 

      Four times as much.

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