Potential energy is the energy an object has due to gravity and its height, proportional to mass, gravity, and height. The unit is the joule (J).
Enter the mass (kg) and height (m) to instantly get the potential energy, using the standard gravity of 9.8 m/s².
For example, a 10 kg object at a height of 5 m has a potential energy of 490 J.
Gravitational potential energy is stored energy an object has because of its height above a reference point. Lift a mass and you store energy; let it fall and that energy converts into kinetic energy.
Enter the mass, the height and the local gravity (9.8 m/s² on Earth) to find the stored energy in joules.
Gravitational potential energy is mass times gravity times height, so lifting 10 kg by 5 m stores 490 J at 9.81 m/s². Dropping that mass converts the store back into kinetic energy and it reaches 9.9 m/s at the ground. The reference height is arbitrary because only differences in height affect the physics.
PE = m × g × hIn a closed system, the total mechanical energy — potential plus kinetic — stays constant. As an object falls, potential energy converts into kinetic energy; as it rises, the reverse happens.
Pumped-storage hydropower is the biggest one: surplus electricity pumps water uphill, and releasing it through turbines later recovers the stored gravitational potential energy when demand peaks.
No. Only changes in height enter the equations, so the zero can be placed anywhere convenient: the ground, a table or the lowest point of the motion. Every consistent choice gives identical answers.
Ignoring air resistance the total is constant, so mgh at the top becomes one half mv² at the bottom. A 20 m fall therefore lands at √(2 × 9.81 × 20) = 19.8 m/s.
2026-10-19