Potential Energy Calculator
Stored energy of height, and the speed it turns into if dropped.
The formula pair
PE = m × g × h v = √(2gh)
Lift 5 kg by 10 m and you've banked 490 J. Drop it and the bank pays out as kinetic energy: it lands at 14 m/s regardless of mass, because the m cancels between PE and KE. Galileo's cannonballs, in algebra.
Height is a battery
Pumped hydro storage is exactly this formula at grid scale: a reservoir 400 m up stores about 1.1 kWh per cubic meter of water. It's the physics behind mechanical energy conservation: E = KE + PE stays constant when nothing rubs.