An object is dropped from rest from a certain height. Air resistance is negligible. After falling a distance, d, the object's kinetic energy is proportional to which of the following? (A) 1/d (B)  d (C) d (D) d2

Answer: (C) d

K. E = P. E loss = mgd

K. E is therefore proportional to d (distance)

Explanation:

According to the law of conservation of energy, which states that energy cannot be created nor destroyed in an isolated system.

Therefore, when an object drops from a certain height the potential energy of the object at that height is gradually convert to kinetic energy as it moves through distance d.

K. E = P. E loss = mgd

K. E is therefore proportional to d (distance)