Velocity and Flow Rate
Lesson 8 Velocity and Flow Rate
Key Concepts
•
Velocity – The speed at which a particle or fluid is moving. Units are distance per
unit of time. (mph, ft/sec)
Velocity = Distance
Time
•
Flow Rate – The rate at which a volume of fluid is moving. Units are
volume per unit of time. (MGD, CFS, gpm)
Q = Velocity x Area
Example 1:
Calculate the velocity in ft/sec if a particle of water travels 30 ft in 1 minute
Example 2:
Calculate the flow rate in CFS if a particle of water travels through a 12 inch pipe
at 3 ft/sec
Example 3:
Calculate the flow rate in gpm of water traveling at 10 ft/sec in a 24 inch pipe
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Calculate water velocity in feet per second:
Velocity = Distance
Time
1. A particle of water travels 60 feet in 15 seconds = _____________ feet per second
2. A particle of water travels 30 feet in 5 seconds = _____________ feet per second
3. A particle of water travels 120 feet in 60 seconds = ___________ feet per second
4. A particle of water travels 200 feet in 1 minute = ___________ feet per second
5. A particle of water travels 1 mile in 2 minutes = _____________ feet per second
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Velocity and Flow Rate
Find the flow rate through the following pipes in cubic feet per second (CFS)
Q = Velocity x Area
6. Flowing at 20 feet per second through a 36 inch pipe = _______________ CFS
7. Flowing at 20 feet per second through a 12 inch pipe = _______________ CFS
8. Flowing at 30 feet per second through a 48 inch pipe = _______________ CFS
9. Flowing at 200 feet per minute through a 36 inch pipe = _______________ CFS
10. Flowing at 150 feet per minute through a 24 inch pipe = _______________ CFS
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Calculate the flow rate through the following pipes in gallons per minute
(gpm)
Remember that 1 cubic foot = 7.48 gallons
11. Flowing at 20 feet per second through a 36 inch pipe = _____________ gpm
12. Flowing at 20 feet per second through a 12 inch pipe = _____________ gpm
13. Flowing at 30 feet per second through a 48 inch pipe = _____________ gpm
14. Flowing at 200 feet per minute through a 36 inch pipe = _____________ gpm
15. Flowing at 150 feet per minute through a 24 inch pipe = _____________ gpm
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