Multiple choice A body weighs 1.5 kg. What is its rest energy in Joules? 15 X 1016 20 X 1016 13.5 X 1016 20 X 1017 Reveal answer Fill a bubble to check yourself C Correct answer Explanation Rest mass energy is E = m0c2 = 1.5 x (3x108)2 = 13.5 x 1016 J. The correct answer is (3)