Exam math · Flow
Flow and velocity
Flow through a pipe or channel is the cross-sectional area times how fast the water moves.
The formula
Q = A x V, with area in square feet and velocity in feet per second giving flow in cubic feet per second.
The unit trap
The exam mixes flow units on purpose: cubic feet per second, gallons per minute, million gallons per day. Write the target unit down before computing and convert as the last step.
Worked practice example
A practice channel with 2 square feet of flow area moving at 1.5 feet per second carries 3 cubic feet per second. (Invented numbers.)
On exam day
A formula and conversion table is provided with the standardized exam; the official version is published by the exam provider at gowpi.org. These pages teach the concepts in our own words so the sheet on the desk reads as a reminder, not a puzzle.
The rest of the math
| Volumes | Tank volume |
| Volumes | Pipe and cylinder volume |
| Flow | Detention time |
| Treatment math | Chemical dosage |
| Treatment math | Percent strength and dilution |
| Treatment math | Removal efficiency |
| Hydraulics | Pressure and head |
| Hydraulics | Pump and horsepower math |
| Foundations | The conversion backbone |
| Foundations | Averages and loading rates |
| Foundations | The formula-first method |
The operator math sheet
One printable page: the exam format, the formula-first drill method, and the unit-conversion discipline that decides the math questions. Free.
No spam. One useful sheet and occasional notes.