a) 14.4 m/s
The problem can be solved by using the law of conservation of total momentum; in fact, the total initial momentum must be equal to the final total momentum:
So we have:
(1)
where
is the mass of each ball
is the initial velocity of the green ball
is the initial velocity of the blue ball
is the final velocity of the green ball
is the final velocity of the blue ball
Simplifying the mass in the equation and solving for , we find
b) 12.0 m/s
This time, the green ball continues moving after the collision at
So the equation (1) becomes
And solving for we find
c) 13.5 m/s
This time, the green ball continues moving after the collision at
So the equation (1) becomes
And solving for we find
