Answer:
Step-by-step explanation:
The equation for this is the one for the Law of Momentum Conservation which says that the momentum before the collision of the balls has to be the same after the collision because momentum cannot be created or destroyed. For us in particular:
and filling in:
[(4.0)(6.0) + (2.0)(0)] = [(4.0 + 2.0)v] and
24 + 0 = 6.0v and
24 = 6.0v so
v = 4.0 m/s to the right