A spaceship of mass 2.20×106 is cruising at a speed of 5.40×106 when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 4.90×105 , is blown straight backward with a speed of 2.40×106 . A second piece, with mass 8.10×105 , continues forward at 1.00×106 .What is the speed of the third piece?