The energy of a body can be calculated using the equation E = mc², where E represents energy, m is the rest mass, and c is the speed of light in a vacuum. The speed of light, c, is a defined constant and does not require calculation from other quantities. To determine the energy of an object, one must measure its rest mass and multiply it by the square of the speed of light. This method provides the rest energy of the body.
PREREQUISITESStudents of physics, educators teaching relativity, and professionals in fields requiring energy calculations based on mass.
DLeuPel said:Since E = mc2 the if I know the mass and the energy I can figure out the constant c2, but how do I know how much energy does the body have ? How do I calculate it ?
thanksPeroK said:Normally you would measure its rest mass, ##m##, and multiply by ##c^2##. That would give you the rest energy, ##E##.
These days ##c## is defined to have a certain value. So, you don't calculate it from other quantities, or from experiment.