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Q: If the air resistance is negligible, then what will be sum of the potential energy and kinetic energy of the freely falling object.
  • A. Endless
  • B. Double the sum of the potential energy
  • C. Zero (
  • D. Constant
Correct Answer: Option D - An object can have both kinetic and potential energy at the same time. For example, an object which is falling freely, but it not yet reached the ground has kinetic energy because it is moving downwards, and potential energy because it is able to move downwards even further than it already has. The sum of an object's potential and kinetic energy is called the object's mechanical energy. As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy. So if the air resistance is negligible then the sum of the potential energy and kinetic energy of an object will remain constant.
D. An object can have both kinetic and potential energy at the same time. For example, an object which is falling freely, but it not yet reached the ground has kinetic energy because it is moving downwards, and potential energy because it is able to move downwards even further than it already has. The sum of an object's potential and kinetic energy is called the object's mechanical energy. As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy. So if the air resistance is negligible then the sum of the potential energy and kinetic energy of an object will remain constant.

Explanations:

An object can have both kinetic and potential energy at the same time. For example, an object which is falling freely, but it not yet reached the ground has kinetic energy because it is moving downwards, and potential energy because it is able to move downwards even further than it already has. The sum of an object's potential and kinetic energy is called the object's mechanical energy. As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy. So if the air resistance is negligible then the sum of the potential energy and kinetic energy of an object will remain constant.