A 3.0 kg mass sliding on a frictionless surface explodes into three 1.0 kg masses. After the explosion the velocities of the three masses are: (1) 9.0 m/s, north; (2) 4.0 m/s, 30 degrees south of west; (3) 4.0 m/s, 30 degrees south of east. What was the magnitude of the original velocity of the 3.0 kg mass?