4. [15 points] A spaceship of mass 2.00 x10^6 kg is cruising ata speed of 5.00 x 10^6 m/s when the antimatter reactor fails,blowing the ship into three pieces.
One section, having a mass of 5.00x10^5 kg, is blown straightbackward with a speed of2.00 x 10^6 m/s.
A second piece, with mass 8.00 x 10^5 kg, continues forward at1.00 x 10^6 m/s.
What are the direction and speed of the third piece?
