A spaceship of mass 2.20 × 106 kilogram is cruising at a speed of 4.70 × 106 m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 4.90 × 105 kilogram, is blown straight backward with a speed of 2.20 × 106 m/s. A second piece, with mass 8.50 × 105 kilogram continues forward at 1.20 × 106 m/s. Evaluate the speed of the third piece?