posted by Anonymous .
a 30 kg girl and a 25 kg boy face each other on friction-free roller blades.the girl pushes the boy,who moves away at a speed of 1.0 m/s.the girl,s speed is _ m/s.
physical science -
The law of conservation of linear momentum
0 = m1•v1 - m2•v2,
v2 =30•1/25 = 1.2 m/s².