multiple choice

Question 1

2. The unit of work is:
   a) Joule
   b) Watt
   c) Newton
   d) Pascal

Answer 1

a) Joule

Question 2

1. Which of the following is a scalar quantity?
   a) Work
   b) Force
   c) Velocity
   d) Acceleration

Answer 2

a) Work

Question 3

3. Work is done only when there is:
   a) A force acting on an object
   b) Displacement of the object
   c) Both force and displacement
   d) None of the above

Answer 3

c) both force and displacement

Question 4

4. The work done by a force is zero if:
   a) The force and displacement are perpendicular to each other
   b) The force and displacement are in the same direction
   c) The force is zero
   d) None of the above

Answer 4

a) The force and displacement are perpendicular to each other

Question 5

5. Which of the following is a form of potential energy?
   a) Kinetic energy
   b) Gravitational potential energy
   c) Thermal energy
   d) Sound energy

Answer 5

b) Gravitational potential energy

Question 6

6. The kinetic energy of an object depends on its:
   a) Mass and velocity
   b) Height and weight
   c) Volume and temperature
   d) Density and speed

Answer 6

a) Mass and velocity

Question 7

7. The energy stored in a stretched rubber band is an example of:
   a) Gravitational potential energy
   b) Chemical potential energy
   c) Elastic potential energy
   d) Nuclear potential energy

Answer 7

c) Elastic potential energy

Question 8

8. The total mechanical energy of an object is the sum of its:
   a) Kinetic and potential energies
   b) Gravitational and elastic energies
   c) Thermal and electrical energies
   d) Magnetic and sound energies

Answer 8

a) Kinetic and potential energies

Question 9

9. According to the work-energy theorem, the work done on an object is equal to the change in its:
   a) Velocity
   b) Acceleration
   c) Momentum
   d) Kinetic energy

Answer 9

d) Kinetic energy

Question 10

10. Which of the following is a non-conservative force?
    a) Frictional force
    b) Gravitational force
    c) Elastic force
    d) Tension force

Answer 10

a) Frictional force

Question 11

11. The area under a force-displacement graph represents:
    a) Work done by the force
    b) Potential energy stored in the system
    c) Kinetic energy of the system
    d) Power exerted by the force

Answer 11

a) Work done by the force

Question 12

12. A machine that has 90% efficiency will waste what percentage of the input energy?
    a) 10%
    b) 20%
    c) 5%
    d) 15%

Answer 12

a)10%

Question 13

13. Which of the following is a unit of work?
    a) Newton-meter
    b) Watt-hour
    c) Joule
    d) All of the above

Answer 13

d) All of the above

Question 14

14. When a car brakes to stop, the energy is converted into:
    a) Kinetic energy
    b) Potential energy
    c) Heat energy
    d) Electrical energy

Answer 14

c) Heat energy

Question 15

15. The work-energy principle can be applied to systems where:
    a) Only conservative forces are involved
    b) Only non-conservative forces are involved
    c) Both conservative and non-conservative forces are involved
    d) No forces are involved

Answer 15

c) Both conservative and non-conservative forces are involved

Question 16

16. Energy cannot be created or destroyed; this statement is known as:
    a) Newton’s third law of motion
    b) Law of conservation of energy
    c) Pascal’s principle

Answer 16

b) Law of conservation of energy

Question 17

17. An object is lifted to a certain height above the ground. What type of energy does it possess at that height?
    a) Kinetic energy
    b) Potential energy
    c) Thermal energy
    d) Chemical energy

Answer 17

b) Potential energy

Question 18

18. Which form of energy is associated with the motion of atoms and molecules?
    a) Kinetic energy
    b) Potential energy
    c) Thermal energy
    d) Sound energy

Answer 18

c) Thermal energy

Question 19

19. In which situation does an object possess the most potential energy?
    a) At rest on the ground level
    b) At rest on top of a hill
    c) Moving at constant speed on a flat surface
    d) Moving at constant speed downhill

Answer 19

b) At rest on top of a hill