A 39.0- body is moving in the direction of the positive x axis with a speed of 361 when, owing to an internal explosion, it breaks into three pieces. One part, whose mass is 7.5 , moves away from the point of explosion with a speed of 475 along the positive y axis. A second fragment, whose mass is 3.5 , moves away from the point of explosion with a speed of 485 along the negative x axis. What is the speed of the third fragment? Ignore effects due to gravity.