Use Einstein’s energy equation to solve the following problem. Recall that the speed of light is 3 × 108 m/s. If a 5.0-kg stone is completely converted to energy, what is its energy equivalent in joules? 4.5 × 10^17 J 1.5 × 10^10 J 1.5 × 10^9 J 4.5 × 10^15 J