Mr. Wilson,
Good morning, I hope this email
finds you well. My name is
Elton Daniels (Town Manager of
Sharpsburg, NC). Last night, Mike
Hill (RWA) came to our Town to
assist us with explaining our water
and sewer rate structure to our
citizens. Since our new rates took
effect (July 1
st
), we have had several
complaints. But based on our past
budgetary deficits, specifically in
our water/sewer fund, increasing
rates was necessary to provide
quality services to our citizens and
meet state mandated debt service
requirements.
While the citizen turnout was not
great last night, Mr. Hill still carried
himself like a professional and did
an awesome presentation.
If ever there is something we can do
to assist you all in the future, please
don’t hesitate to contact me directly.
I copied Mike Hill and Tracy
Sullivan (Town Clerk) on this email.
Sincerely,
E.D.
--
Elton Daniels, MPA
Town Manager
Sharpsburg, NC
Office Phone: 252-446-9441
THE NCRWA MAILBOX
A 6-inch diameter water line has a flow
of 170 gallons per minute. What is the
velocity of the water in feet per second?
Tools and Parts needed:
The formula (tool) to find velocity is Flow Rate (Q) divided by Area (A). This is expressed as: Q A
The units (parts) that are needed are:
Flow Rate (Q) – The units must be Cubic Feet per Second
Area (A) – The units must be Square Feet
The steps to solve the problem are:
Step 1: Determine what the question is asking you to find.
(The question tells you to find the water velocity in feet per second)
Step 2: Determine what formula (tool) to use.
(The formula is - Flow Rate (Q) divided by Area (A) or: Q A
Step 3: Find the flow rate given in the question and convert it to the correct unit needed.
The unit (part) needed to work the formula is cubic feet per second but the flow rate given in the
question is 170 gallons per minute. You have the wrong part for your engine. You must change
the part (gallons per minute) for the right part (cubic feet per second). To do this you divide
170 gallons by 7.48 gallons per cubic foot, that will give you 22.7 cubic feet per minute.
Then divide 22.7 cubic feet per minute by 60 seconds per minute to change it to cubic feet per
second. 22.7 divided by 60 = 0.378 cubic feet per second. This is your flow rate in cubic feet
per second, you now have the right part.
Step 4: Find the diameter of the pipe given in the question and convert it to the area in square feet.
The question tells you that it is a 6 inch pipe. You must use another formula (tool) to find the
area of the 6 inch pipe. The formula is:
3.14 times radius squared which is the same as 3.14 times radius times radius (3.14 X R X R).
The unit (part) needed is square feet but the question gives you 6 inches. You must change the
inches to feet by dividing by 12. 6 inches divided by 12 inches per foot = 0.5 feet, this is your
pipe diameter in feet. You must change the pipe Diameter in feet to the pipe Radius in feet. To
do this you divide the 0.5 feet diameter by 2. 0.5 feet divided by 2 = 0.25 feet, this is your
radius in feet. Now you can find the area using the formula 3.14 X R X R. Replace each “R”
with the number 0.25 and multiply (3.14 X 0.25 feet X 0.25 feet = 0.196 square feet) this is
the area of the 6 inch pipe.
Step 5: Divide the flow rate (in cubic feet per second) that you calculated in Step 3 by the
Area (in square feet) that you calculated in Step 4. (0.378 cubic feet per second divided by
0.196 square feet = 1.93 feet per second, this is the velocity of the water.
When working math problems it is very important, just like tuning an engine, to make sure you
use the right part (unit) and the right tools (formulas). You will find that it is easier to remember
the steps if you work a practice problem over and over again until the steps become easy for
you to remember. Eventually it will be as easy as tuning up your lawnmower.
Winter 2014 |
NCRWA.COM
21
correspondence
