Kinetic Energy
When something is in motion it is said to have kinetic energy. The formula for an object that is moving the kinetic energy equals one half times the mass of
When you lift a heavy object you exert energy which later will become kinetic energy when the object is dropping.This topic is recommendable for all enthusiastic physicists.

http://hypertextbook.com/physics/mechanics/projectiles/
This is a mechanics topic suitable for advanced learners of physics mainly senior five.
It explains on how the force of gravity, causes a projectile to accelerate in the downward direction.