- #1
mknob001
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Homework Statement
Water flows in the pipe below as an ideal fluid where:
P1 = 1.95*10^5 Pa ; Rad @ P1 = 3cm
P2 = 1.20*10^5 Pa ; Rad @ P2 = 1.50 cm
P2 is above P1, but the height difference is UNKNOWN.
Questions:
1. What are the velocities at P1 and P2?
2. Find volume flow rate through the pipe.
I don't have a diagram, but it's pretty simple - known pressures with known radii at UNKNOWN heights.
Homework Equations
P1 = P2 + dgh -- doesn't this assume the areas are the same? (which they aren't)
Bernoulli's.
A1V1 = A2V2
The Attempt at a Solution
1. I used A1V1 = A2V2 to solve the ratio between V1 and V2 (since rad can be used to find A) and solved for v1.
2. I substituted answer for v1 into v1 of bernoulli's equation. This way I can get v2.
BUT, I can't solve Bernoulli's eq. without knowing the heights, h1 and h2.
3. I though P1 - P2 = dgh could work, but I thought this was only for change in height with the same area. Am I wrong?
Help would be much appreciated. I'm so stuck on this whole different areas/heights/pressures thing and my brain is shutting down a bit from the frustration. Haha help?