What is kinetic and potential energy

Kinetic energy is energy possessed by an object in motion.

The earth revolving around the sun, you walking down the street, and molecules moving in space all have kinetic energy.

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity:

K.E. = 1/2 m v² . If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second square.

Kinetic energy is usually measured in units of Joules (J); one Joule is equal to 1 kg m² / s².

Potential energy is energy an object has because of its position relative to some other object.

The formula for potential energy depends on the force acting on the two objects. For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s² at the surface of the earth) and h is the height in meters.

Notice that gravitational potential energy has the same units as kinetic energy, kg m² / s². In fact, all energy has the same units, kg m² / s², and is measured using the unit Joule (J).