if you refer to the speed of the water as it falls, it is at 9.8m/s
3160 tons every second
150,000 gallons per seconed
Yes, rainwater can contain minerals that it picks up as it falls through the atmosphere and interacts with the environment.
No, rainwater is formed when water vapor in the atmosphere condenses and falls to the ground as precipitation. Urine is excreted by animals, including humans, and is commonly not mixed with rainwater.
Rainwater tanks are used to catch rainwater which falls from the sky when precipitation occurs. This is a great water saving device which can cut the cost of your water bills.
Reservoirs which collect the rainwater that falls in the catchment areas.
carbonic acid
110 000 m3 (average); see also http://en.wikipedia.org/wiki/Niagara_Falls.
Yes, there is snow that falls in Glencoe, Scotland in the month of December.
150,000 gallons per second
Yes. Some places, such as the island of Bermuda, have giant catchment basins to gather all the rainwater that falls on the island, because Bermuda has no fresh water wells or springs.