Watch Class D operator math solved by hand
Pick a problem. Work it in your own notebook first, on paper or a chalkboard, with your choice of pens. Stuck? The hints come one at a time. When you are ready, watch the whole thing written out slowly, with an explanation under every step that a third grader could follow.
- Water & wastewaterHow much pressure does 92 feet of water make?A storage tank's water sits 92 feet above a house. Ignoring friction, how much water pressure does that height make at the house?Try it, then watch →
- Water & wastewaterHow many gallons are in a 20 by 10 by 8 foot tank?A tank is 20 feet long, 10 feet wide, and holds water 8 feet deep. How many gallons does it hold?Try it, then watch →
- WaterHow many gallons are in a 30 foot round tank?A round tank is 30 feet across and holds water 32 feet deep. How many gallons does it hold?Try it, then watch →
- Water & wastewaterHow many pounds of chlorine for 2 MGD at 3 mg/L?You treat 2 MGD (million gallons a day) of water at a dose of 3 mg/L. How many pounds of chlorine do you need per day?Try it, then watch →
- Water & wastewaterHow do you turn 350 GPM into gallons per day?A pump runs steadily at 350 gallons per minute (GPM). How many gallons per day is that?Try it, then watch →
- WastewaterWhat is the detention time of a 30,000 gallon tank?A tank holds 30,000 gallons, and the flow through it is 10,000 gallons per hour. What is the detention time in hours?Try it, then watch →