Matter can be converted into energy through processes like particle annihilation and nuclear reactions, as described by E=mc^2. In this equation, 'c' represents the speed of light, serving as a constant that relates mass to energy. Achieving the speed of light is impossible for objects with mass, which means one cannot simply run at that speed to convert matter into energy. To effectively convert the mass of a body into energy, one would need to annihilate it with an equal amount of antimatter. This highlights the complexities and limitations of matter-energy conversion.