Kinetic energy


The kinetic energy has always been present in our daily lives in different ways. This is generated through the acceleration of a body until reaching an indicated speed . The adjective “kinetic” is given to this type of energy because it is generated through movement .

  • Unit:  July
  • Symbol:  J
  • Formula:  Ec = ½ mv²

What is kinetic energy?

Kinetic energy or energy of motion is that produced by the motion of an object and is linked to its mass and speed . It is abbreviated with the letters Ec or Ek and can be of two types, rotational or translational and molecular.

  • features
  • History
  • What is it for
  • What does it depend on
  • Units
  • Formula
  • Types
  • Translational and rotational kinetic energy
  • Molecular kinetic energy
  • Examples


Among the characteristics of kinetic energy , the following can be mentioned:

  • It is produced by the movement of a body.
  • Increases with speed.
  • It is greater the greater the mass of the body that produces it
  • It is measured in Joules.
  • It can be transformed into heat or other types of energy.


The history of kinetic energy has been scientifically studied from the end of the 18th century by the German philosopher and mathematician Gottfried Leibniz and by the Swiss mathematician and physician Johann Bernouilli , who baptized it with the name of “living force” or “vis viva ” . Years later, the Dutch Willem’s Gravensade carried out research confirming the importance of vis viva and it was twice what is currently known as kinetic energy. Gravensade threw weights on a clay surface in order to measure the penetration capacity of thrown objects. With this experiment,determined that when throwing an object with double mass, the distance that it sank into the clay was double . On the other hand, if he threw two weights with the same mass, one at twice the speed of the other, the speed with which the weight penetrated faster was four times as deep. If the speed tripled the hole became nine times greater. In this sense, it is proportional to the result of multiplying the mass times the speed twice.

The concept that is currently being used , makes its appearance in the mid- nineteenth century thanks to the contributions of the French scientist Gaspard-Gustabe Corioli s in 1829 and is defined by the British physicist William Thomson (also known as Lord Kelvin) in the year 1850 .

What is it for

Kinetic energy allows us to generate changes that are related to speed . This can be transformed into other types of energy such as light, hydro or wind energy that can produce electricity to move many of the daily devices that we use on a day-to-day basis , in household appliances such as the blender, the ventilated one, in our environments of transport , in our workplace, entertainment etc.

What does it depend on

It depends on the movement and the mass that produces this movement . The greater the movement and the greater the mass, the greater the generation of kinetic energy.


Kinetic energy is measured in Joules (J) , its mass in kilograms (kg) and its velocity in meters over seconds (m / s)


The formula used to calculate the kinetic energy is the following: Ec = ½ mv² .


Kinetic energy can be of two types:

  • Of translation and rotation .
  • Molecular .

Translational and rotational kinetic energy

The kinetic energy of translation occurs when the parts of an object move in the same direction, for example when we walk.

The rotational energy is generated when a rotating body , for example a mill.

As you can see, both types are related to displacement in one direction or around its axis.

Molecular kinetic energy

The molecular kinetic energy occurs in molecules of the material at normal temperatures encountered in constant motion high speed .


Here are some examples of kinetic energy:

  • Driving a bicycle generates translational kinetic energy that can generate another type of light energy, such as the dynamo placed on the bicycle wheel that allows light to be generated while the bicycle is moving.
  • The car of a roller coaster generates this type of energy when descending one of its slopes.
  • A sailing ship generates kinetic energy when moving in the sea. If there are two boats with different sizes, the one with the greater mass will be able to move faster than the smaller one. This is because the kinetic energy is higher in relation to the body that produces it.
  • Mills Wind also generate this energy to the rotating its blades.
  • When running we also generate it. In this case it will be determined by speed and our moving body mass.

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