An unstable atomic nucleus of mass 17.0 3 10227 kg initially at rest disintegrates into three particles. One of the particles, of mass 5.00 3 10227 kg, moves in the y direction with a speed of 6.00 3 106 m/s. Another particle, of mass 8.40 3 10227 kg, moves in the x direction with a speed of 4.00 3 106 m/s. Find (a) the velocity of the third particle and (b) the total kinetic energy increase in the process.