What does the c in mc2 stand for?

Answer 1

The energy contained with in an object of mass "m" is equal to that mass times the speed of light, squared.

Or Energy = mass X speed of light X speed of light

Einstein surprised the scientific world with this equation showing the equivalence of mass and energy. Because the speed of light is such a large number (299 792 458 m / s), much larger when it is squared (8.98755179 × 10^16 m^2/s^2), a very small amount of mass can yield a huge amount of energy. This is why nuclear reactions are so efficient - just a small amount of fissile material can power a city (or blow it up).

It wasn't until 37 years after Einstein first published this equation that it was shown experimentally. On December 2, 1942, man first initiated a self-sustaining nuclear chain reaction, and controlled it.

In 2005, the centennial of Einstein's great year, a team made the most accurate test yet of his equation. They measured the tiny change in mass of radioactive atoms before and after the atoms emitted gamma-rays. And they measured the energy of the rays. The missing mass times c² equaled the energy of the rays to within 4 hundred-thousandths of one percent.)

Answer 2

The "c" in (E=mc^2) stands for the speed of light, which is approximately 299,792,458 meters per second.

Answer 3

c2 is the speed of light squared