What is the relationship between energy and mass according to Einstein?

Answer 1

E=MC2

energy=mass*(speed of light in a vacuum)squared

so say you lose 0.001kg of mass, thats

E=0.001*1,079,252,848.8km/h

E=1,079,252.8488

so 1,079,252.8488 joules of energy for every gram of mass lost

Answer 2

According to Einstein's theory of relativity, energy and mass are equivalent and can be converted into each other. This is represented by the famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light in a vacuum. This equation demonstrates that a small amount of mass can be converted into a large amount of energy, as seen in nuclear reactions.