A 394 kg mass is brought close to a second mass of 138 kg on a frictional surface with coefficient of friction 0.6. At what distance will the second mass begin to slide toward the first mass?The acceleration of gravity is 9.8 m/s2 and the value of the universal gravitational constant is 6.67259 × 10-11 N · m2/kg2. Answer in units of mm.