Imagine holding a ball in the air, what energy is involved in each part of this situation & how do we know that total mechanical energy has been conserved? Explain with and without air resistance present.

Conservation of mechanical energy

Explanation:

Law of Conservation of Mechanical Energy: The total amount of mechanical energy, in a closed system in the absence of dissipative forces (e. g. friction, air resistance), remains constant.

In the absence of air resistance, the mechanical energy of an object moving through the air in the Earth's gravitational field, remains constant (is conserved) while the opposite is the case when there is air resistance involved.