Someone Explain e=mc2 to me.?

Question

Yes, yes. I need to know.

Answer 1

Below is an answer I wrote about the relationship between mass and energy. The mass of an object is actually dependent on the stability of the object. We do notice this in our everyday lives. But it is very apparent in nuclear reactions.



E = mc^2

The letter E is energy

The letter, m, in this equation means mass.

The letter, c, is the speed of light = 299,792,458 m/, which we usually round to 3 * 10^8 m/s



This equation is used to determine the amount of energy produced in nuclear reactions.

Below I have the reaction equation for the radioactive decay of the nucleus of a Radium atom.



Ra → Rn + α + energy

α = alpha particle

A specific isotope of Radium decays into a specific isotope of Radon. One mole of Radium nuclei produces one mole of alpha particle and one mole of Radon nuclei.



Reactant

The mass of one mole of Radium nuclei = 226.025406 grams



Products

The mass of one mole of Radon nuclei = 222.017574 grams

The mass of one mole of alpha particle = 4.002603 grams

Total mass of products = 226.020177 grams



Mass of Reactant – Mass of Products = 0.005229 grams = 5.229 * 10^-6 kg



When 1 mole of Radium nuclei decayed, it produced 1 mole of Radon nuclei and 1 mole of alpha particle.



Using Einstein’s equation:

Energy = mass * c^2

Energy = 5.229 * 10^-6 * (3 * 10^8)^2 = 4.7061 * 10^11 Joules of energy



When this nuclear reaction occurs in nature, 4.7061 * 10^11 joules of energy is actually produced.





The BIG QUESTION is what happened to the 5.229 * 10^-6 kg??



Let’s look at the reactant and products and determine what nuclear particles are missing.



A specific isotope of Radium decays into Radon.

The Radium nucleus contains 88 protons and 138 neutrons.

The Radon nucleus contains 86 protons and 136 neutrons.

The alpha particle is the nucleus of a Helium atom which contains 2 protons and 2 neutrons.



Radon + alpha = 86 p + 136 n + 2 p + 2 n = 88 protons and 138 neutrons



All the nuclear particles of the Radon nucleus are in the nucleus of Radium + alpha particle. So, no nuclear particles were converted into energy during the nuclear decay reaction.



Mass is missing, but no particles are missing. Energy has appeared, but where was the energy before it was produced.



Radium is radioactive. This means the nucleus is unstable. The nucleus contains protons with a positive charge and neutrons that are neutral. Positive particles repel each other. For protons to be close to each other, a force must exist that is stronger than the repelling force. This force, called the strong nuclear force, attracts protons and neutrons towards each other.



Fact #1

The energy required to hold a Radium nucleus together is greater than the total energy required to hold a Radon nucleus together and an alpha particle together.

4.7061 * 10^11 Joules is the energy difference.



Fact #2

1 mole = 6.02 * 10^23

1 mole of Radium nuclei contains 6.02 * 10^23 nuclei.

Each nucleus contains 88 protons and 138 neutrons.

One mole of Radium nuclei contains

6.02 * 10^23 * 88 protons = 5.2976 * 10^25 protons

and 6.02 * 10^23 * 138 neutrons = 8.3076 ^ 10^25 neutrons



When the 5.2976 * 10^25 protons and 8.3076 ^ 10^25 neutrons are in the Radium nucleus, the total mass = 226.025406 grams



Fact #3

When the 5.2976 * 10^25 protons and 8.3076 ^ 10^25 neutrons are in the Radon nucleus and the alpha particle, the total mass = 226.020177 grams



Fact #4

The mass of 5.2976 * 10^25 protons and 8.3076 ^ 10^25 neutrons in a Radium nucleus is 5.229 * 10^-6 kg greater than the mass of 5.2976 * 10^25 protons and 8.3076 ^ 10^25 neutrons in a Radon nucleus and an alpha particle.



Conclusion #1

The mass of each proton and each neutron is greater when they are in a Radium nucleus than when they are in a Radium nucleus and an alpha particle.



Conclusion #2

Mass is dependent on the stability of an object.

When an object is most stable, its mass is the lowest.

When an object is less stable, its mass is greater





So, energy is produced during a nuclear reaction, because the protons and neutrons have become more stable.



Conclusion #3

During a nuclear reaction, matter is not converted into energy. During a nuclear reaction, matter becomes more stable.



I hope this helps you to understand how Einstein’s equation applies to nuclear reactions.



If you have other questions that you would like me to answer, make me one of your contacts. You questions will come directly to my yahoo email address.

Answer 2

In his special TOR AE wrote that inertia M = m/sqrt(1 - (v/c)^2) and total energy E of an electron with rest mass m accelerated slowly so as to not slough off radiant energy was E = Mc^2 = mc^2/sqrt(1 - (v/c)^2).



On rearranging terms and factors, we find that E^2 = e^2 + k^2 where E = Mc^2, e = mc^2 (yes that one), and k = Mvc is the kinetic energy of that electron while moving at v speed.



So e^2 = E^2 - k^2 and e = mc^2 = sqrt(E^2 - k^2). And there you are. e = mc^2 is that part of a rest mass' total energy that is not kinetic energy. In this STOR, AE developed this for the mass of an electron but wrote it was applicable to all mass.



The best interpretation of e = mc^2 is that the mass, m, is a form of stored energy that can be, and has been under special circumstances, released as working energy (typically radiant energy). This is the energy released by nuke power plants and A-bombs for example.



Note, this does not...not...say the energy and mass are the same thing. But it does say one can be converted into the other, and the other can be converted back into the one. That is m = e/c^2 is just as valid as e = mc^2.



One more point, e = mc^2 does not mean the mass m is going light speed c. In fact m is called the rest mass because it's at rest...stationary. The c^2 comes from something called the Lorentz Transformations during the derivation in the STOR.

Answer 3

It is the relationship between

mass and energy



Energy = Mass x (Speed of Light)^2

Answer 4

It seems you himself once will explain this to me. Outhor is absence.