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E = mc2
You can calculate the equivalence between mass and energy using the special theory of relativity.
Explanation
The law of conservation of relativistic momentum applies. Energy can change it's form in a short period of time. An increase in energy is sometimes the product of force and distance traveled. In doing so, the force then causes a change in momentum per time. Therefore you can write
Substitution of the relativistic mass then gives
We use the chain rule 
and first determine the derivative to v and get
To this we apply the product rule
which you can convert to
This can be written as
and that apparently is (but I can't explain that)
This shows that change in energy is equal to change in mass multiplied by the square of the speed of light.
HistoryGerman physicist Albert Einstein (1879 - 1955) and French mathematician Henri Poincaré (1854 - 1912) developed this formula. |