Fluid Dynamics Question: A glass tube areas, pressure, determine height.

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The discussion revolves around a fluid dynamics problem involving a glass tube with varying cross-sectional areas and a piston exerting pressure to move mercury at a speed of 8.0 m/s. Participants emphasize the application of the Bernoulli equation to analyze the pressure and velocity changes at different points in the tube. Key parameters include the atmospheric pressure of 1.01×10^5 Pa and the density of mercury at 13,600 kg/m³. The goal is to determine the height of mercury in the manometer, with potential answers ranging from 136 mm to 371 mm. The thread highlights a need for guidance due to missed learning on fluid dynamics concepts.
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http://home.cc.umanitoba.ca/~loly/102-dec_word.pdf
The above is a link to the problem - Question #3.

Homework Statement



A glass tube has several different cross-sectional areas with the values indicated in the figure. A piston at the left end of the tube exerts pressure so that the mercury within the tube flows from the right end with a speed of 8.0 m/s. Three points within the tube are labeled A, B, and C.
Point A 12cm^2
Point B 5.6cm^2
Point C 6.0cm^2
NB: The drawing is not to scale.
Atmospheric pressure is 1.01×105 m/s2; and the density of mercury is 13 600 kg/m3.
Determine the height h of mercury in the manometer with the evacuated upper end.
(a) 136 mm (b) 269 mm (c) 276 mm (d) 366 mm (e) 371 mm

Homework Equations



I really don't know where to start with this question, so any help would be appreciated here.

Atmospheric pressure is 1.01×105 m/s2
density of mercury is 13 600 kg/m3

Pressure = force / area, p = F/A

The Attempt at a Solution



As above, not really sure where to start with this as I missed our week of learning about fluid dynamics and am now playing greaaat catch up. Would greatly appreciate the help!
--
 
Last edited:
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ReMa said:
http://home.cc.umanitoba.ca/~loly/102-dec_word.pdf
The above is a link to the problem - Question #3.

Homework Statement



A glass tube has several different cross-sectional areas with the values indicated in the figure. A piston at the left end of the tube exerts pressure so that the mercury within the tube flows from the right end with a speed of 8.0 m/s. Three points within the tube are labeled A, B, and C.
Point A 12cm^2
Point B 5.6cm^2
Point C 6.0cm^2
NB: The drawing is not to scale.
Atmospheric pressure is 1.01×105 m/s2; and the density of mercury is 13 600 kg/m3.
Determine the height h of mercury in the manometer with the evacuated upper end.
(a) 136 mm (b) 269 mm (c) 276 mm (d) 366 mm (e) 371 mm

Homework Equations



I really don't know where to start with this question, so any help would be appreciated here.

Atmospheric pressure is 1.01×105 m/s2
density of mercury is 13 600 kg/m3

Pressure = force / area, p = F/A

The Attempt at a Solution



As above, not really sure where to start with this as I missed our week of learning about fluid dynamics and am now playing greaaat catch up. Would greatly appreciate the help!
--
Start by applying the Bernoulli equation to the right end and the contracted center section.
 
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