What does e equals mc squared actually mean?

Answer 1

Formally it is written as

E = mc^(2)

E = Energy ( joules)

m = mass ( kg)

c = speed of light in a vacuum (m/s; metres per second)

c^(2) = speed of light squared ( m^2/s^2) or (m/s)^2

Note how similar it is to kinetic energy

K.E. = (0.5) m v^(2)

KE is Kinetic Energy

m = mass

v = velocity(speed) .

Answer 2

It was discovered in 1905 by the scientist Albert Einstein that E = mc2 where E is energy m is mass and c is the square of the speed of light in a vacuum.