A 765-kg two-stage rocket is traveling at a speed of 6.80×103m/s away from Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move by a speed of 2.90×103m/s relative to each other along the original line of motion. How much energy was supplied with the explosion? [Hint: What is the change in kinetic energy as a result of the explosion?]