Kinetic Energy Equations Definition Newtonian Mechanics

For non-relativistic mechanics, the total kinetic energy of a body can be considered as the sum of the body's translational kinetic energy and its rotational energy, or angular kinetic energy:

For the translational kinetic energy of a body with mass m, whose centre of mass is moving in a straight line with linear velocity v, we can use the Newtonian approximation:

Thus, for a speed of 10 m/s the kinetic energy is 50 J/kg, for a speed of 100 m/s it is 5 kJ/kg, etc.

1.3 Relativistic mechanics

It is an edifying exercise to show that the ratio of this relativistic kinetic energy to the Newtonian kinetic energy given by (1/2)mv^{2 approaches 1 as v approaches 0, i.e.,}

Relativity theory states that the kinetic energy of an object grows towards infinity as its velocity approaches the speed of light, and thus that it is impossible to accelerate an object to this boundary.

Where gravity is weak, and objects move at much slower velocities than light (e.g. in everyday phenomena on Earth), Newton's formula is an excellent approximation of relativistic kinetic energy.

The next term in the approximation is 0.375 mv⁴/c², e.g. for a speed of 10 km/s this is 0.04 J/kg, for a speed of 100 km/s it is 40 J/kg, etc.

2 Heat as kinetic energy

HeatCommonly, heat is estrus, a period of increased sexual drive in female mammals. For the National Basketball Association team, see Miami Heat. For the movie, see Heat (movie). Heat (abbreviated Q also called heat change is the transfer of thermal energy be is a form of energy due to the total kinetic energy of moleculeIn science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. A molecule consists of multiple atoms joined by shared pairs of electrons in a covalent bond''. It may consist of atoms and atomFor alternative meanings see atom (disambiguation). An atom is a microscopic structure found in all ordinary matter around us. Atoms are composed of 3 types of subatomic particles: electrons, which have a negative charge; protons, which have a positive chs of matter. The relationship between heat, temperatureTemperature is the physical property of a system which underlies the common notions of "hot" and "cold"; the material with the higher temperature is said to be hotter. General description The formal properties of temperature are studied in thermodynamics. and kinetic energy of atoms and molecules is the subject of statistical mechanics. Heat is more akin to work in that it represents a change in internal energy. The energy that heat represents specifically refers to the energy associated with the random translational motion of atoms and molecules in some identifiable matter within a system. The conservation of heat and mechanical work form the first law of thermodynamics.

See Boltzmann constant and heat capacity.

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Home > Kinetic energy

1 Equations

1.1 Definition

1.2 Newtonian mechanics

1.3 Relativistic mechanics

2 Heat as kinetic energy

3 See also

Topics: Kinetic Energy, Equations, Definition, Newtonian Mechanics...