Please explain Einstein's equation E=mc2.

Question

i need just a simple explanation of it. thanks!

Answer 1

The simplest explanation: For any given quantity of matter, there is an equivalent quantity of energy. Putting energy into something makes it heavier. Taking energy out of something makes it lighter.

Answer 2

I am no math whiz but it is pretty self explanatory when they say E=mc2. it means that E=mc2. LOL. Sorry but i don't know

Answer 3

Einstein was a quack as far as I can tell.  While many of his theories have practical applications he was dead wrong in a number of them and absolutely refused to believe in anything that disproved or antagonized one of his ideas.  Quantum physics greatly troubled him and during his life he would not accept the evidence at hand.  

Some people have given a simple explanation of that equation so I just figured I'd throw in an opinion about him.  Furthermore, the idea that because some of his theories and equations work well for the here and now makes them correct is absurd.  Almost all of classical mechanics falls apart at two levels; quantum and universal.  

But, directly to your question... E=mc^2 is a sometimes incorrect equation mostly used in nuclear physics.  It stands for energy equals resting mass times the speed of light squared to be completely correct and only applies to particles with both a resting mass and no kinetic energy or momentum.  Particles are known to exist with no resting mass and the equation in question is typically used to find changes in energy since almost everything has some amount of kinetic energy (except those with no resting mass.)  Total energy is a different equation and many college educated people don't realize this.  

Answer 4

FURTHER MORE TO WHAT HAVE BEEN SAID,

Einstein was briliant to find out the relation between mass and energy, how he found that the constant to be multiblied by mass gives energy is a mistry at leastto me . this constant in itself is a miracle (light speed to the power 2)

however when any mass transmitted to energy, this equation is correct as in neucliar reactors,

also it is correct even in burning...say wood, if you have a mass of wood and you managed to measure the energy comes out from burning and also you can collect all burning products (not missing even smoke particles) and after that you calculate the loss of matter's mass..you will find the equation is corrct too.

Answer 5

In E=MC2, E is energy, M is mass and C is the speed of light. Thus MC2 proves that energy is equal to the amount of mass multiplied by the speed of light squared. We can further understand it by saying that every body has mass and a certain amount of energy. This formula gives a relation of energy and mass when they transform into each other. For example: a nuclear explosion, where E is the energy let out when a certain amount of mass was eradicated.

Answer 6

I am not sure that what follows here, is a simple explanation but it is at least a simpler derivation of the famous energy-mass equivalence equation!  

The famous equation (E=mc²) was derived by Einstein as part of his 1905 paper 'On the Electrodynamics of Moving Bodies'. This theory is now better known as the ‘Theory of Special Relativity’. Its underlying concepts were that wherever an observer is located he or she must find the laws of physics to be the same and furthermore, whatever the observer’s velocity he or she must find the speed of light to have the same value. The speed of light is a universal upper limit to all velocities. To allow observers with different velocities to transform their results so that they agreed, Einstein provided a transform equation: -

x = x'/sqrt(1 -(v/c)²)

Thus measurement x for one observer, separating from another observer with a constant velocity v, can be transformed into the other observers measurement x’.

The famous equation is derived from the expression for work energy. Work equals force times distance.

dW = F.ds

Since force F equals d(mv)/dt and ds/dt = v we can expand the expression for work into: -

dW =(d(mv)/dt).ds

or, expanding further: -

dW=v²dm+mv.dv

Using the observers transform equation for masses (x = m, x’ = m’) we can obtain

m²c² = m²v² + m'²c²

Differentiating, with c and m' as constants, gives: -

2mc²dm = 2mv²dm + 2m²vdv

When the 2m is divided out, we are left with: -

dW = c²dm

Thus integrating between limits m and m' (the rest mass) with c constant gives:-

W = c²∫dm = c²(m - m')

Or (since the total work is the energy): -

E = mc² + m'c²

This is not Einstein's original derivation but I hope you find it perhaps a bit easier going than his briefer, but for all that, calculus rich approach.

  

Answer 7

U know law of conservation of energy: that energy can neither be created nor destroyed similarly law of conservation of mass says that : mass of a system remains constant

Einstein combined both these and proposed that mass and energy are interconvertible and energy associated with a mass is given by

E = mc^2. This is an important eqn in Nuclear Science

Answer 8

E = M C^2 is such a powerful formula that researchers are still trying to understand its full range and scope.

As I understand it, the equation says that E (energy) is equal to M (mass at speeds close to that of light) times k (constant of light speed squared).  The equation suggest that as Mass increases, the roughly equivalent amount of energy decreases [ E / M = C^2 ]. And this is consistent with what happen after the big-bang formation of the universe. At the time of the big-bang, all energy and forces were unified into just one form, pure energy. As the universe spread out and cooled, energy began to decrease and mass began to increase toward rest-mass.  Matter formed, gravity developed and started clumping matter (mass) together to form structures in the universe as we know it today.

That is how powerful Einstein's simple equation is.

Out of the two variables, (E and M), ignoring the constant of speed of light, you can plug different equations that have energy and/or mass in them into Einstein's basic equation, E = MC^2, and see how different aspects of our classical world behaves at zero energy, or zero mass,  infinite energy, or infinite mass.  From this, it gives a good indication about how the world and the universe evolved over time, a very, very long period of time.

Here's an example: F (force) = M (mass) x a (acceleration). If you rearrange the equation and solve it for mass, you have: M = F / a.  Now take F / a and plug it into Einstein's equation, E = M C^2.  You will get E = (F / a) C^2.  From this, you can see that if C^2 remains constant, if E increases, you can then determine how that increase in energy will affect force, F, and acceleration, a.

That is very, very powerful.  Try it.  Look for equations in physics with mass and energy in them, rearrange these equations for F and M and plug them into E = M C^2 and see how these other varables change with change in energy.

Who knows, you might discover a new law of nature.

See: What is the mass of a photon

http://math.ucr.edu/home/baez/physics/Pa...