Can you please derive the formula for mass-energy relation with brief explanation? How mass is converted into energy?

Why in equation E=Mc^{2}, c (velocity of light)is taken?

Has it anything to do with mass-energy?

Please answer me.

Answer:

Mass is converted to energy in nuclear reactions – during nuclear fusion as well as fission.

The following link has the necessary details. Please go through it.

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

http://library.thinkquest.org/3471/energy_mass_equivalence.html