Question

What should be measured to calculate the average rate at which water flows in a dam?

Distance of water flow and duration of water flow
Number of liters of water flowing and duration of water flow
Distance of water flow and size of the dam from which water flows
Number of liters of water flowing and size of the dam from which water flows

Answer 1

@phi

Answer 2

average rate at which water flows in a dam?

you measure the amount of water using units such as quart, gallon or liter.
(some measure of volume)
rate would be a ratio of "amount" per "time"
so I would look for an answer that has amount of water and length of time.