The amount of work required to stop a moving object is equal to:
Correct answer: B. The kinetic energy of the object
- A. The velocity of the object
- B. The kinetic energy of the object
- C. The mass of the object times its velocity
- D. The weight of the body
Explanation
The correct answer is Option B: The kinetic energy of the object. According to the work-energy principle, the work done on an object to stop it is equal to the change in its kinetic energy, which in this case is the initial kinetic energy of the object since it is being brought to rest.Option A is incorrect because velocity alone does not quantify the work needed. Option C is incorrect as it describes force, not work. Option D is incorrect because it describes momentum, which is not directly related to the work done to stop the object.
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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