An unstable nucleus of mass 1.70 x 10-26 kg, initially at rest at the origin of a coordinate system, disintegrates into three particles. One particle, having a mass of m1 = 5.90 x 10-27 kg moves in the positive y-direction with speed v1 = 6.20 x 106 m/s. Another particle, of mass m2 = 8.40 x 10-27 kg moves in the positive x-direction with speed v2 = 4.70 x 106 m/s. Find the velocity of the third particle. (Assume that mass is conserved in this process. Indicate the direction with the sign of your answer.)