Starting from rest, two skaters 'push off' against each other on smooth level ice, where friction is negligible. As the drawing shows, one is a woman (m1 = 54 kg), and one is a man (m2 = 88 kg). Part b of the drawing shows that the woman moves away with a velocity of vf1 = +5.5 m/s. Find the "recoil" velocity vf2 of the man.