Answer:
Mass will not change based on location, while weight will change based on gravitational pull.
Explanation:
The formula for weight is mass*gravitational pull, hence weight changes based on gravitational pull
Apply the law of conservation of momentum for this situation. The law states that the momentum of a system is constant (in absence of external forces acting on it).
The 'system' in this case are the two skaters. There is no external force on the skaters. Suppose the skaters are initially standing still. The momentum in the system is 0. This value will need to remain constant, even after the mutual push (which is a set of forces from <em>inside</em> the system). So we know that
(total momentum before) = (total momentum after)
Indexing the masses and velocities by the first letter of the skaters' names:

From the last row, you can see that the skaters will have momentum of same magnitude but opposite direction, after the push off. That answers the first question: neither will have a greater momentum (both will have one of same magnitude).
Since Ricardo is heavier, from the above equality it follows that

In words, Paula has the greater speed, after the push-off.
Answer:
<em>The amount of water in circulation is the same</em>
Explanation:
The water cycle is the pathway in which water moves from the atmosphere to the earth and back to atmosphere ones again.
During the sunny period, the temperature of the earth is heated up, water evaporates to the atmosphere as water vapour. The water vapour gathers as cloud and comes back to the earth as rain, which enters our rivers and stream. Thereby maintaining a continuous cycle.
With the water cycle, the movement of water via precipitation and evaporation is the same on earth.

In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents flowing through each component.
In a series circuit, every device must function for the circuit to be complete. If one bulb burns out in a series circuit, the entire circuit is broken.