MDCAT Work and Energy MCQs

This comprehensive set of MCQs on Work and Energy is designed to cover all essential topics required for success in the Medical and Dental College Admission Test (MDCAT). Focused on key subjects such as the Work-Energy Theorem, Kinetic and Potential Energy, Power, and the Conservation of Energy, these MCQs are crafted to help aspiring medical and dental students build a strong understanding of the fundamental concepts of energy and their applications in health sciences.

Who should practice Work and Energy MCQs?

Students preparing for the MDCAT who wish to deepen their understanding of the principles of work, energy, and power, which are vital for biomechanics and medical physics.
Individuals seeking to enhance their knowledge of energy transformations, efficiency, and the role of energy in physiological processes.
University students targeting high-yield topics like mechanical work, energy conservation, and their applications in medical technology and human health.
Anyone aiming to strengthen their foundational understanding of energy concepts and their implications in biological systems and medical applications.
Candidates focused on developing critical thinking and analytical skills related to solving physics problems and applying energy principles in real-world scenarios.

1. What is the SI unit of work?

A) Joule
B) Newton
C) Watt
D) Pascal

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2. Which of the following is a scalar quantity?

A) Force
B) Work
C) Velocity
D) Acceleration

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3. The work done by a force is zero when:

A) The force is perpendicular to the direction of motion
B) The force is parallel to the direction of motion
C) The object moves in the direction of the force
D) The object moves in the opposite direction to the force

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4. What is the formula for kinetic energy?

A) ½ mv²
B) mgh
C) Fd
D) mv

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5. Potential energy is the energy possessed by an object due to its:

A) Motion
B) Speed
C) Position
D) Mass

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6. The gravitational potential energy of an object is given by:

A) ½ mv²
B) mgh
C) Fd
D) ½ kx²

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7. Which of the following statements is true about power?

A) Power is the rate at which work is done
B) Power is the rate at which force is applied
C) Power is the total energy used by a machine
D) Power is the force applied over a distance

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8. The SI unit of power is:

A) Joule
B) Newton
C) Watt
D) Pascal

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9. What is the work done when a force of 10 N moves an object 5 meters in the direction of the force?

A) 2 Joules
B) 15 Joules
C) 50 Joules
D) 5 Joules

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10. Kinetic energy is directly proportional to:

A) The mass of the object only
B) The square of the object’s velocity
C) The object’s acceleration
D) The distance the object moves

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11. If an object is lifted to a height of 10 meters, what type of energy does it gain?

A) Kinetic energy
B) Gravitational potential energy
C) Thermal energy
D) Electrical energy

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12. Which of the following describes work in terms of physics?

A) The force applied to an object
B) The movement of an object in the direction of the applied force
C) The speed at which an object moves
D) The displacement of an object

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13. The work-energy principle states that:

A) Work done on an object is equal to the change in its kinetic energy
B) Work done on an object is equal to its velocity
C) Work is always equal to potential energy
D) Work is independent of energy

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14. How is power related to work done and time?

A) Power = Work × Time
B) Power = Work / Time
C) Power = Force × Time
D) Power = Work / Force

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15. Which of the following has the highest kinetic energy?

A) A stationary car
B) A moving car
C) A falling object
D) A compressed spring

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16. Gravitational potential energy depends on:

A) The height, mass, and gravitational force on an object
B) The velocity and position of the object
C) The acceleration of the object
D) The angle of inclination of the surface

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17. What is the relation between work and energy?

A) Work is the rate at which energy is used
B) Work is the transfer of energy
C) Energy is the force acting over a distance
D) Work and energy are unrelated

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18. If the mass of an object is doubled, what happens to its kinetic energy?

A) It doubles
B) It halves
C) It remains the same
D) It quadruples

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19. The gravitational potential energy of a body increases with:

A) Decreasing height
B) Increasing height
C) Increasing speed
D) Decreasing mass

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20. In what unit is energy measured?

A) Watt
B) Newton
C) Joule
D) Pascal

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21. If an object has zero kinetic energy, which of the following could be true?

A) It is moving at a constant velocity
B) It is at rest
C) It is accelerating
D) It is at maximum height

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22. What does the term “mechanical energy” refer to?

A) The sum of kinetic and potential energy in a system
B) Only the potential energy in a system
C) The energy produced by machines
D) The total work done on a system

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23. The rate at which energy is transferred or transformed is called:

A) Work
B) Force
C) Power
D) Potential energy

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24. If the velocity of an object is tripled, how does its kinetic energy change?

A) It doubles
B) It triples
C) It remains the same
D) It increases nine times

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25. Work done against gravity is referred to as:

A) Kinetic work
B) Gravitational potential work
C) Vertical work
D) Negative work

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26. Which form of energy does a compressed spring possess?

A) Kinetic energy
B) Potential energy
C) Thermal energy
D) Chemical energy

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27. When is no work done by a force on an object?

A) When the object is stationary
B) When the force is applied perpendicular to the motion
C) When the force is applied in the opposite direction
D) When the object moves at a constant speed

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28. What is the relationship between power and energy?

A) Power is the rate of energy transfer
B) Power is the sum of kinetic and potential energy
C) Power is the total amount of energy used
D) Power and energy are the same

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29. Which of the following is an example of work being done?

A) Holding a heavy box stationary
B) Pushing a car up a hill
C) Standing still
D) Sitting on a chair

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30. In the absence of external forces, the mechanical energy of a system:

A) Increases
B) Decreases
C) Remains constant
D) Is zero

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31. Which of the following quantities is a measure of an object’s ability to do work?

A) Force
B) Energy
C) Power
D) Displacement

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32. What is the unit of energy in the CGS system?

A) Erg
B) Joule
C) Calorie
D) Watt

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33. Which of the following defines potential energy?

A) Energy due to motion
B) Energy due to position or condition
C) Energy due to temperature
D) Energy due to mass

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34. If a person lifts a 20 kg box to a height of 2 meters, what is the work done against gravity? (Take g = 9.8 m/s²)

A) 196 J
B) 392 J
C) 98 J
D) 20 J

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35. What is the power output of a machine that does 3000 joules of work in 10 seconds?

A) 300 watts
B) 3000 watts
C) 30 watts
D) 30000 watts

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36. Which factor affects the amount of kinetic energy an object has?

A) Its temperature
B) Its velocity
C) Its shape
D) Its density

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37. What happens to the potential energy of an object as it falls freely under gravity?

A) It increases
B) It decreases
C) It remains constant
D) It becomes zero

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38. Power is defined as:

A) The amount of force applied over a distance
B) The rate of doing work
C) The total energy used by a machine
D) The speed at which an object moves

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39. Which of the following statements about work is correct?

A) Work is independent of distance
B) Work is the product of force and distance moved in the direction of the force
C) Work is a vector quantity
D) Work is measured in newtons

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40. When does an object have maximum gravitational potential energy?

A) At the lowest point of its motion
B) At the highest point of its motion
C) When it is in motion
D) When it is moving at maximum speed

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41. If a car’s speed doubles, what happens to its kinetic energy?

A) It doubles
B) It triples
C) It remains the same
D) It quadruples

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42. What is the work done by a force of 5 N acting on an object that does not move?

A) 0 J
B) 5 J
C) 10 J
D) 15 J

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43. The rate at which energy is converted from one form to another is called:

A) Work
B) Power
C) Energy transformation
D) Force

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44. How much work is done when a 10 N force moves an object 3 meters horizontally?

A) 3 J
B) 10 J
C) 30 J
D) 0 J

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45. Which form of energy does a moving object have?

A) Kinetic energy
B) Potential energy
C) Thermal energy
D) Chemical energy

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46. An object lifted to a certain height gains potential energy. If the mass of the object is doubled, what happens to the potential energy?

A) It doubles
B) It halves
C) It remains the same
D) It quadruples

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47. A 100-watt light bulb uses how much energy in 1 second?

A) 1 joule
B) 10 joules
C) 100 joules
D) 1000 joules

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48. Which of the following is true about gravitational potential energy?

A) It depends on the object’s height above the ground
B) It depends on the object’s velocity
C) It is always equal to kinetic energy
D) It is measured in watts

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49. Work done by a force is equal to:

A) Force × displacement
B) Force ÷ displacement
C) Displacement ÷ force
D) Force + displacement

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50. Which of the following is a non-mechanical form of energy?

A) Chemical energy
B) Kinetic energy
C) Potential energy
D) Gravitational energy

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51. What happens to the total mechanical energy of a system when only conservative forces are acting?

A) It increases
B) It decreases
C) It remains constant
D) It fluctuates

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52. What is the work done by gravity on a falling object?

A) Positive
B) Negative
C) Zero
D) Depends on height

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53. If a force of 15 N is applied at an angle of 30° to the horizontal and the object moves 5 meters, what is the work done by the force?

A) 37.5 J
B) 65 J
C) 15 J
D) 75 J

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54. When does an object have maximum kinetic energy?

A) At the lowest point in its motion
B) At the highest point in its motion
C) When it is at rest
D) When it is in equilibrium

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55. The efficiency of a machine is the ratio of:

A) Output power to input power
B) Input power to output power
C) Work done to time taken
D) Force to distance

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56. How much energy is used by a 500-watt machine in 10 seconds?

A) 500 J
B) 5000 J
C) 50 J
D) 50000 J

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57. The energy stored in a compressed spring is an example of:

A) Kinetic energy
B) Elastic potential energy
C) Chemical energy
D) Gravitational potential energy

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58. In which of the following scenarios is work being done?

A) Holding a book above your head
B) Carrying a box horizontally
C) Pushing a car that is not moving
D) Pulling a sled across snow

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59. What is the gravitational potential energy of a 10 kg object raised to a height of 5 meters? (g = 9.8 m/s²)

A) 490 J
B) 980 J
C) 50 J
D) 49 J

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60. What happens to the kinetic energy of an object if its mass is tripled but its velocity remains constant?

A) It triples
B) It doubles
C) It remains the same
D) It halves

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61. What is the unit of power in the SI system?

A) Joule
B) Newton
C) Watt
D) Erg

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62. Which of the following describes kinetic energy?

A) Energy stored in a body at rest
B) Energy due to an object’s motion
C) Energy due to an object’s position
D) Energy released during a chemical reaction

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63. The work-energy theorem states that the work done on an object is equal to:

A) The force applied
B) The object’s kinetic energy
C) The change in kinetic energy
D) The object’s potential energy

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64. How much work is done when lifting a 2 kg object to a height of 10 meters? (g = 9.8 m/s²)

A) 19.6 J
B) 98 J
C) 196 J
D) 9.8 J

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65. Which quantity remains constant when a roller coaster moves from its highest point to its lowest point, assuming no friction?

A) Kinetic energy
B) Potential energy
C) Mechanical energy
D) Work

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66. Power is the rate at which:

A) Energy is stored
B) Work is done
C) Force is applied
D) Speed changes

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67. What is the kinetic energy of a 5 kg object moving at a speed of 4 m/s?

A) 40 J
B) 80 J
C) 16 J
D) 32 J

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68. If an object’s velocity is halved, what happens to its kinetic energy?

A) It doubles
B) It halves
C) It becomes one-fourth
D) It remains the same

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69. The gravitational potential energy of an object depends on:

A) Its mass and speed
B) Its height and speed
C) Its mass and height
D) Its acceleration and mass

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70. What is the relationship between power and work?

A) Power is the rate of work done
B) Power is the force applied to do work
C) Power and work are inversely proportional
D) Power equals work divided by distance

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71. A 1000-watt motor does 1000 joules of work in:

A) 1 second
B) 10 seconds
C) 100 seconds
D) 0.1 second

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72. Which of the following represents the formula for gravitational potential energy?

A) P.E. = mv²/2
B) P.E. = mgh
C) P.E. = 1/2 mv²
D) P.E. = ma

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73. When an object falls freely under gravity, what happens to its potential and kinetic energy?

A) Potential energy decreases, and kinetic energy increases
B) Potential energy and kinetic energy both increase
C) Potential energy increases, and kinetic energy decreases
D) Both remain constant

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74. The unit of work in the SI system is:

A) Joule
B) Watt
C) Erg
D) Newton

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75. If two objects have the same mass but different velocities, which has more kinetic energy?

A) The object with greater velocity
B) The object with lower velocity
C) They have the same kinetic energy
D) It depends on their height

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76. A 500-watt machine uses how much energy in 5 seconds?

A) 500 J
B) 2500 J
C) 1000 J
D) 100 J

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77. Which of the following is a scalar quantity?

A) Force
B) Displacement
C) Work
D) Acceleration

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78. If a person lifts a 10 kg object to a height of 2 meters, how much gravitational potential energy does it gain? (g = 9.8 m/s²)

A) 19.6 J
B) 196 J
C) 9.8 J
D) 98 J

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79. Which of the following quantities is equal to power?

A) Energy × time
B) Work × distance
C) Work ÷ time
D) Force ÷ time

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80. In the absence of air resistance, what happens to the total mechanical energy of a falling object?

A) It decreases
B) It remains constant
C) It increases
D) It fluctuates

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81. What is the work done on a 5 kg object that is moved 10 meters horizontally with a force of 20 N?

A) 50 J
B) 100 J
C) 200 J
D) 20 J

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82. Which of the following describes potential energy?

A) Energy due to motion
B) Energy stored in a position
C) Energy due to force
D) Energy lost during motion

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83. The kinetic energy of an object depends on:

A) Its mass and velocity
B) Its mass and height
C) Its force and acceleration
D) Its displacement and time

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84. What is the power of a machine that does 150 joules of work in 3 seconds?

A) 50 watts
B) 30 watts
C) 450 watts
D) 500 watts

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85. If the mass of an object is doubled and its velocity remains the same, how does its kinetic energy change?

A) It doubles
B) It halves
C) It quadruples
D) It remains the same

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86. In which case is no work done?

A) A book is lifted upward
B) A person pushes a wall
C) A car accelerates on a road
D) A ball is thrown upward

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87. Which of the following is the formula for work?

A) Work = force ÷ distance
B) Work = force × distance
C) Work = energy ÷ time
D) Work = force + time

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88. Which of the following quantities is measured in watts?

A) Force
B) Energy
C) Power
D) Work

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89. A 2 kg object is thrown upwards with a velocity of 10 m/s. What is its kinetic energy?

A) 50 J
B) 100 J
C) 200 J
D) 20 J

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90. How much work is done when a force of 12 N moves an object 5 meters?

A) 60 J
B) 12 J
C) 5 J
D) 24 J

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91. A 10 kg object is held 2 meters above the ground. What is its gravitational potential energy? (g = 9.8 m/s²)

A) 98 J
B) 196 J
C) 20 J
D) 9.8 J

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92. What happens to the energy of an object when work is done on it?

A) Energy increases
B) Energy decreases
C) Energy remains constant
D) Work and energy are unrelated

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93. The rate at which work is done is referred to as:

A) Force
B) Power
C) Energy
D) Momentum

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94. If a machine does 3000 J of work in 10 seconds, what is its power output?

A) 3 W
B) 300 W
C) 3000 W
D) 30 W

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95. When a person pushes against a stationary object and it doesn’t move, the work done is:

A) Zero
B) Equal to the force applied
C) Maximum
D) Infinite

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96. Which of the following factors does NOT affect gravitational potential energy?

A) Mass
B) Height
C) Speed
D) Gravitational acceleration

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97. What is the kinetic energy of a 4 kg object moving with a speed of 6 m/s?

A) 36 J
B) 72 J
C) 144 J
D) 288 J

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98. A force of 15 N moves an object 3 meters. How much work is done?

A) 3 J
B) 15 J
C) 45 J
D) 30 J

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99. If an object is raised to twice its original height, what happens to its potential energy?

A) It is halved
B) It doubles
C) It quadruples
D) It remains the same

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100. Which of the following is a correct expression for power?

A) Power = force × distance
B) Power = work ÷ time
C) Power = energy × distance
D) Power = time ÷ work

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