The 4.9x10^5 N final stage of a spaceship ejects the 9x1065 N second stage. If before ejection, the two stages

the 4.9x10^5 N final stage of a spaceship ejects the 9x1065 N second stage. If before ejection, the two stages travel at 756kph and after the ejection the second stage travels at the opposite direction at 198kph of its initial motion, determine the final velocity of the final stage.