Answer:
9.18 m/s
Step-by-step explanation:
Momentum is conserved.
The heavier ball has a momentum (arbitrarily defined as positive) of ...
Mv = (8.2 kg)(14.6 m/s) = 119.72 kg·m/s
The lighter ball has a momentum of ...
Mv = (3.3 kg)(-4.3 m/s) = -14.19 kg·m/s
So the total momentum is ...
119.72 -14.19 = 105.53 . . . . kg·m/s
After the collision, the total mass is ...
8.2 kg +3.3 kg = 11.5 kg
That mass with the total momentum has a velocity of ...
(105.53 kg·m/s)/(11.5 kg) = 9.1765... m/s
The common velocity is about 9.18 m/s.