2 people,1 with 3 times the mass of the other, attempt a tug-of-war on frictionless ice. Show that the heavier person will gain a speed 1/3 that of the lighter person.

Answer 1

momentum before = 0*m + 0 * 3m = 0
momentum after =u *m + v*3m
momentum after = momentum before
um+3vm=0
vm = -um/3
v = -u/3