A ball is thrown from the top of a building. As it approaches the ground which of the following decreases?
Potential energy
Potential energy, PE=m×g×h
where m is the mass, g is the acceleration due to gravity and h is the height above the ground.
The total mechanical energy of an object is constant if conservative forces act on that object.
In the given case, as the ball approaches the ground, its height above the ground decreases. Due to this, the potential energy decreases and kinetic energy increases.