2. A rocket of mass 800 kg is fired vertically upward (+y). It reaches an altitude of 1000 m and a velocity of 400 m/s. At this instant the rocket explodes into three fragments. One fragment of 350 kg continues to move upward with a speed of 420 m/s right after the explosion. The second fragment of 200 kg has a speed of 250 m/s moving horizontally (+x) right after the explosion. What are the magnitude and direction of the third fragment's velocity. ?