physics momentum

1. In process (2), the total kinetic energy completely vanished. It is possible only if the collision is perfectly inelastic.

2. Initial momentum before collision = (2m/3)[sqrt(2gh1)]
where m is the mass of ball A.
Total final momentum after collision
= (2m/3).[sqrt(2gh1)] + (2m/3)[sqrt(2gh1)]
= (4m/3).[sqrt(2gh1)]
Momentum seems NOT conserved.

3. I don't think you could. The initial speed of the box is necessary in claculating angle theta.

4. I suppose you are asking for the situation when a person of larger mass collidies with one with a lower mass.

In this case, the impact forces acting on both of them are the same.

2014-07-30 22:50:23 補充：
Your suppl questions:
1. Air pucks collision cannot be perfectly inelastic.

2014-07-30 22:52:56 補充：
2. The masses of ball A and B are m and 2m respectively.
Thus their corresponding momenta are (m).(2/3)[sqrt(2gh1)] and (2m).(1/3)[sqrt(2gh1)]

may i ask why initial momentum before collision is (2m/3)[sqrt(2gh1)] but not m[sqrt(2gh1)]? hope you will see this thanks!