Kinetic Energy vs. Potential Energy

Main Difference

The main difference between Kinetic Energy and Potential Energy is that the Kinetic Energy is a energy possessed by an object by virtue of its motion and Potential Energy is a form of energy.

• Kinetic Energy

  In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.

  In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is

  1

  2

  m

  v

  2

  {displaystyle {begin{smallmatrix}{frac {1}{2}}mv^{2}end{smallmatrix}}}

  . In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.

  The standard unit of kinetic energy is the joule.

• Potential Energy

  In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.

  Common types of potential energy include the gravitational potential energy of an object that depends on its mass and its distance from the center of mass of another object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit for energy in the International System of Units (SI) is the joule, which has the symbol J.

  The term potential energy was introduced by the 19th century Scottish engineer and physicist William Rankine, although it has links to Greek philosopher Aristotle’s concept of potentiality. Potential energy is associated with forces that act on a body in a way that the total work done by these forces on the body depends only on the initial and final positions of the body in space. These forces, that are called conservative forces, can be represented at every point in space by vectors expressed as gradients of a certain scalar function called potential.

  Since the work of potential forces acting on a body that moves from a start to an end position is determined only by these two positions, and does not depend on the trajectory of the body, there is a function known as potential or potential energy that can be evaluated at the two positions to determine this work.