Two rocks collide in outer space. Before the collision, one rock had mass 13 kg and velocity < 4500, -2900, 2600 m/s. The other rock had mass 6 kg and velocity <-650, 2200, 3600 m/s. A 1 kg chunk of the first rock breaks off and sticks to the second rock. After the collision the 12 kg rock has velocity < 1600, 250, 1900 m/s. After the collision, what is the velocity of the other rock, whose mass is now 7 kg?