Gravitational Potential Energy

Gravitational potential energy (GPE) increases when an object is raised and decreases when it falls.

$\Delta E_p = mg\Delta h$

where $m$ is mass (kg), $g$ is gravitational field strength (N/kg), and $\Delta h$ is the change in vertical height (m).

When an object falls freely with no air resistance, its GPE converts entirely to kinetic energy. This principle allows you to find the speed at any height without knowing the time.