So I have to present a solution to a physics problem in class on wednesday and I am a little confused on some of the terminology on the problem. I'll put the problem then ask my questions. any help would be greatly appreciated. FYI, I can't ask my teacher because I haven't been to school in over a week.

A 975 kg two-stage rocket is traveling at a speed of 5.8x10^3 m/s (or 5800 m/s) with respect to Earth when a pre-designed explosion separates the rocket into two sections of equal mass that then move at a speed of 2.20x10^3 m/s (2200 m/s) relative to each other along the original line of motion.

a)What are the speed and direction of each section (relative to Earth) after the explosion?

b)How much energy was supplied by the explosion? [Hint: What is the change is KE (kinetic energy) as a result of the explosion]

***The first road block I am at is the phrase "relative to each other along the original line of motion." Does this mean that the combined speed of the two rockets after the explosion is 2200 m/s? Or does this mean that it is a vector and the velocity up added to the velocity down is equal to 2200m/s I can't start the problem till I figure this out.