- 671

- 16

^{2}.

http://www.adamauton.com/warp/emc2.html

But I don't if this shorthand derivation is O.k. or not.

like the derivation, I use maxwells law and say the momentum p is given by

p = E / c ---> 1

Now from newtonian mechanics, we have

p= m* v

or, p=mc (here v=c) --->2

Combining 1 and 2

mc = E / c

therfore, E = mc

^{2}

What's wrong here?

If its wrong, why is the result correct?

If its correct, why didn't Einstein use it?