Question

1 kilogram mass is equal to energy​

Answer 1

1 joule is the answer

Answer 2

1 kilogram of matter is equivalent to an energy E = (1 kg)×(3×108 m/sec)2 = 9×1016 kg m2/sec2.

An energy of 1 kg m2/sec2 is known as 1 joule, for short. The joule is not a unit of energy that is used much in everyday life.