Simple volume flow rate calculation

Click For Summary
The discussion centers on calculating the volume flow rate in a pipe with varying diameters and speeds. The user initially struggles with the formula, believing that combining the areas and speeds might be necessary. It is clarified that the volume flow rate can be calculated using the formula Q = Av for each segment, ensuring that the radius is used instead of diameter. The user realizes a mistake in unit conversion, which led to incorrect answers. Ultimately, consistent application of the formula across all segments should yield the same volume flow rate.
Metalsonic75
Messages
28
Reaction score
0
[SOLVED] Simple volume flow rate calculation

A 1.0-cm-diameter pipe widens to 2.0 cm, then narrows to 0.5 cm. Liquid flows through the first segment at a speed of 4.0m/s. The speed in the second segment is 1m/s, and the speed in the 3rd segment is 16 m/s

I thought that volume flow rate was simply Av, but I've tried many combinations of the 3 cross-sectional areas and 3 speeds with no success. Do I need to add them all up and multiply? Do I need to take averages? Oh, and should I have my units in terms of meters or centimeters? I'm really baffled as to why my answers aren't working, because I know it's a fairly simple problem. Any help would be appreciated. Thanks
 
Physics news on Phys.org
All three should give the same answer when multiplying the area and the velocity. Check your units and that you're using radius not diameter.
 
Got it. I was off by a factor of 10. Thanks
 
Thread 'Correct statement about size of wire to produce larger extension'

Thread 'Correct statement about size of wire to produce larger extension'

The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...
View full post »

Similar threads

Speed/Velocity and Volume Flow Rate of Viscous Fluids
  • · Replies 5 ·
Replies
5
Views
2K
Poiseuille equation for water flow rate
  • · Replies 16 ·
Replies
16
Views
2K
Calculate flow rate in a tap and the height of a reservoir
  • · Replies 5 ·
Replies
5
Views
3K
Bernoulli equation for calculation of water flow
  • · Replies 30 ·
2
Replies
30
Views
3K
The Pressure Distribution in a Narrowing Tube with Increasing Fluid Velocity
  • · Replies 10 ·
Replies
10
Views
4K
Calculating Volume Flow Rate of Olive Oil at a Processing Plant
  • · Replies 1 ·
Replies
1
Views
2K
Maximum height for water from a fire hose
  • · Replies 4 ·
Replies
4
Views
4K
Flowmetry Analysis (relating height to flow rate)
  • · Replies 1 ·
Replies
1
Views
2K
Calculate Volume Flow Rate in Ideal Liquid Flow: Homework Solution
  • · Replies 1 ·
Replies
1
Views
2K
Fluid Flow rate and fluid dynamics
  • · Replies 15 ·
Replies
15
Views
2K