Question

Suppose the total mechanical energy of an object is conserved. Which one or more of the following statements is/are true?

A) If the kinetic energy decreases, the gravitational potential energy increases

B) If the gravitational potential energy decreases, the kinetic energy increases

C) If the kinetic energy does not change, the gravitational potential energy also does not change

D) All of the above E) None of the above

Answer 1

The law of conservation of total mechanical energy states that sum of kinetic energy and potential energy of a system remains constant.

So if kinetic energy of a system decreases then the gravitational potential energy(it will also true for different kind of potential energy ,for eg Coulombic potential energy) have to increase by the same amount to which kinetic energy decreases as sum of both two remains constant.

Now in similar way if kinetic of a system increases then by same amount gravitational potential energy of the system will decrease.

If kinetic energy does not change then also potential energy will not change.

So that option (D) is correct.

I am attaching some short notes related to conservation of mechanical energy.

Kindly look on those notes.

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