Question

A 10k bike is rolling down a hill at a velocity of about 2.5 m. Where would the kinetic energy be the lowest and where would it be the highest? Where would the potential energy be the lowest and the highest? Explain your logic.

Answer 1

The given problem can be exemplified in the following diagram:

We are given that the bike starts at a height of 2.5 meters. Since the potential energy is a function of the height, as the height decreases the potential energy will decrease too. Also, due to the conservation of energy, the sum of the potential and kinetic energy of the bike remains constant.

In point 1, where the bike is at the highest point the potential energy must be maximum and the kinetic energy must be a minimum.

In point 2, as the bike decreases its height its potential energy also decreases, but since the sum of kinetic and potential energy must remain constant, as the potential energy decreases the kinetic energy must increase, therefore, the kinetic energy is a maximum and the potential energy is a minimum.