In a vacuum, all objects fall at the same rate. Meaning that the 100 kg ball will fall at the same speed as the 10 kg ball. Assuming that both objects share the same starting acceleration, they will keep that acceleration until the fall is stopped.
In other words, your answer is the first one, Both objects will accelerate at 9.8 m/s
I can answer the first question: Water rises because of the sun's heat and turns into water vapor. After that, it gathers up and forms a cloud. When the cloud is filled enough with vapor, precipitation occurs.
You do it by the pressure difference it causes in the medium. Even in transversal waves, you usually need different units than meters because the wave has electric and magnetic vectors and not really any height to speak of.
you measure the amount of excursion from the equilibrium (no wave) level of whatever parameter is fluctuating.
Answer:
frequency measured in megahertz
