Potential Energy

Potential energy is the energy an object holds because of its position rather than its motion. The most familiar form is gravitational potential energy — the energy stored in an object simply because it is elevated above a reference point, such as the ground. A boulder perched on a cliff edge, a roller coaster car at the top of its first hill, and water held behind a dam all possess gravitational potential energy that can be converted into motion the moment they are released.

The Potential Energy Calculator applies this directly: given an object's mass and height above a reference level, it computes the stored energy in joules using standard Earth gravity. This calculation is used across engineering and physics to estimate the energy available in hydroelectric dams, the impact force of falling objects, and the design of amusement park rides.

Potential energy is one half of the mechanical energy equation, working alongside Kinetic Energy. As height decreases during a fall, potential energy is converted into kinetic energy at the same rate, so the two together remain constant in an idealized system without friction or air resistance.

PE = m × g × h

Where PE is gravitational potential energy (in joules, J), m is mass (in kilograms, kg), g is gravitational acceleration (9.8 m/s² on Earth), and h is height above the reference point (in meters, m).

A 5 kg object is lifted to a height of 10 meters above the ground. Its gravitational potential energy is:

PE = 5 kg × 9.8 m/s² × 10 m = 490 joules

If the object is dropped, this 490 joules of potential energy converts almost entirely into kinetic energy by the time it reaches the ground (ignoring air resistance), which can be used with the Kinetic Energy formula to find its impact velocity.

• Scales linearly with both mass and height: doubling either the mass or the height doubles the potential energy, unlike kinetic energy, which scales with the square of velocity.
• Depends on a chosen reference point: potential energy is always measured relative to a baseline height, often the ground or a table surface, so the same object can have different PE values depending on what reference is used.
• Converts directly into Kinetic Energy: as height decreases during free fall, potential energy transforms into kinetic energy, conserving total mechanical energy in the absence of air resistance.
• Zero at the reference height: an object at the chosen zero-height level has no gravitational potential energy relative to that point, even if it still has mass.
• Not the only type of potential energy: this gravitational form (PE = mgh) is distinct from elastic potential energy in springs or chemical potential energy in fuels, though all describe stored, position-dependent energy.