12. A 3.4 kg grenade initially at rest explodes into three pieces. A piece of 1.2 kg is heading southwest at a speed of 5.3 m/s. A second piece of 0.9 kg is heading at [N 30' E] at a speed of 4.1 m/s. Determines the vector velocity of the third piece. 0.9 kg 30 hilal weight=3.4 kg. 1.2 kg 450