Question

an object with mass 10kg is at rest. It explodes into 4 pieces. A peice with mass 3kg travels NORTH at 5m/s, another piece 5kg travels at 30(degrees) NORTH of EAST at 2 m/s, and another piece 1.1kg travels 60(degrees) NORTH of WEST at 7 m/s. Find the mass and path of the fourth piece.