# The Dirty Word of Math/Physics Education

A good way to distinguish between the two modes of memorization is to look at two multiple-choice questions involving the well known equation, $E=mc^2$. First question:

The relativistic equation stating the equivalence of mass and energy is

• $E=mc^3$
• $E=m^2c$
• $E=mc^2$
• $E=mc^4$
• $E=m^3c$

Second question:

If you could convert one kilogram of mass completely into energy in a large power plant that by itself supplies energy to a medium-sized city, for how long would that energy last? Assume that the plant has an output of one gigawatt and the speed of light is 300 million meters per second.