what is e=mc2?

Answer 1

The equation is properly written E=mc2, with the '2' written as a superscript (which we can't display in this text editor), and pronounced "E equals em see squared".

It's an equation in physics giving the energy content of matter. If an amount of matter has mass 'm', then the energy content of that matter is 'E'. In the equation, 'c' is the speed of light.

Since 'c' is a very large number (c=300,000,000 meters per second, approximately), there is a lot of energy contained in even a small amount of matter.

Example: If you took a U.S. 5 cent coin, which weighs about 5 grams, and converted it completely into energy, you would liberate 0.005 kilograms x 300,000,000 meters/sec x 300,000,000 meters/sec = 450,000,000,000,000 joules of energy. This is equal to 450,000,000 megajoules, or 125,000,000 kilowatt-hours. The average household (U.S.) uses about 12,500 kilowatt-hours of electrical energy per year, so this amount of energy would power about 10,000 households for a year, if it was in the form of electrical energy.

In other words, there is a lot of energy contained in even a small amount of matter.

The equation was derived by Albert Einstein, and is part of his Special Theory of Relativity, which was published in 1905 in the scientific journal Annalen der Physik. The title of the paper is "On the Electrodynamics of Moving Bodies."

Many people think that E=mc2 only applies to nuclear reactions, or even just to nuclear explosions, but this is not the case. In fact it applies generally to all transformations of matter, including chemical transformations such as combustion and even respiration in living organisms. Any time energy is liberated, mass is lost, and conversely, any time energy is converted into potential form, mass is gained. It's just that, in chemical reactions, the amount of mass gained or lost is so small compared to the mass of the reacting stuff, that it can't be measured by even the best scales. Even in nuclear reactions, only a small amount of the matter in the splitting (or fusing) atoms is converted into energy. The only reactions where matter is completely turned into energy (i.e. where there is no matter left over after the reaction is complete) is when matter combines with antimatter.

Answer 2

E = mc2 is one of the most famous equations, even to non-physicists, and which states a relationship between energy (E), in whatever form, and mass (m). In this formula, c², the square of the speed of light in a vacuum, is the conversion factor required to formally convert from units of mass to units of energy, i.e. the energy per unit mass. In unit specific terms, E (joules) = M (kilograms) multiplied by (299792458 m/s)2.

The equation was first published in a slightly different formulation by Albert Einstein in 1905 in one of his famous articles. He derived it as a consequence of the special theory of relativity which he had proposed the same year.

Answer 3

And according to Eric Idle e=mc2 is the meaning of life.

Answer 4

why complicate things ?
the speed of light is 1 and never changes
1 light year per year
1 light seccond per seccond
1 squared is 1
energy = mass
am i wrong somewhere or wouldnt it be simpler to have a standard unit of energ measurement based on this ?

Answer 5

E = Energy
M = Mass
C = Speed of light squared

Answer 6

Einstein equation
c=speed of light
m=mass

Answer 7

It is a set of mathematical symbols representing a natural balance in nature between various orientations of energy..

Answer 8

E = energy
m = mass
c = speed of light

So energy = mass x speed of light x speed of light

:)

Amanda

Answer 9

energy=mass times the speed of light squared.

Answer 10

the theory of relativity, which is created by albert einstein

e - energy
m - mass
c - speed of light