Fluid Manometer Question: Determining Height and Pressure

  • Thread starter Thread starter LauraMorrison
  • Start date Start date
  • Tags Tags
    Fluid Manometer
Click For Summary

Discussion Overview

The discussion revolves around a fluid manometer problem involving water and kerosene, focusing on determining the height and pressure in the U-tube under different conditions. The scope includes homework-related problem-solving and mathematical reasoning.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • The initial height H0 is given as 20 mm, and the participant calculates the height h as 91.1 mm for part (i) of the problem.
  • There is uncertainty regarding whether the height h remains constant when a gauge pressure of 98 Pa is applied to the right end of the U-tube.
  • One participant asserts that the total length of the kerosene column does not change in part (ii), while another participant questions this assertion based on their lecturer's solutions.
  • A participant expresses confusion about the lecturer's solutions and seeks clarification on the relationship between h and H0 under the applied pressure.

Areas of Agreement / Disagreement

Participants do not reach a consensus regarding whether the height h changes with the applied pressure. There are competing views on the interpretation of the problem, particularly concerning the behavior of the kerosene column.

Contextual Notes

There is a lack of clarity on the assumptions made regarding the relationship between h and H0, as well as the implications of the applied pressure on the system. The discussion reflects differing interpretations of the problem based on varying sources.

LauraMorrison
Messages
25
Reaction score
0

Homework Statement



The manometer illustrated in Fig. Q2 contains water and kerosene (specific
gravity of 0.82) as indicated. With both ends of the U-tube open the height
H0 =20 mm.
(i) Determine the height, h , when both ends of the tube are open. [4]
(ii) Determine the new value of H0 when a gauge pressure of 98 Pa is
applied to the right end of the U-tube. [6]


2. The attempt at a solution

I can do part (a), getting an answer of 91.1mm.

However, I am stuck on part (b).. I assume I cannot keep h constant and see the variation in Ho with the added pressure?

I am unsure how to work out the two unknowns h and Ho with only the one equation.
 

Attachments

  • u-tube manometer.jpg
    u-tube manometer.jpg
    7.4 KB · Views: 1,687
Physics news on Phys.org
In part (i), you determined h, so, from the figure, you now know that total length of the kerosene column. This doesn't change in part (ii).
 
Are you sure h doesn't change? In my lecturers solutions it does change.. I don't really understand his solutions but maybe you can explain?

I have attached his solution.
 

Attachments

LauraMorrison said:
Are you sure h doesn't change? In my lecturers solutions it does change.. I don't really understand his solutions but maybe you can explain?

I have attached his solution.

I didn't say h doesn't change. I said that the total length of the kerosene column doesn't change.

Chet
 
Oh I see, sorry I didn't read that carefully enough. Thank you I get it now! :)
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 26 ·
Replies
26
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
2
Views
2K
Replies
1
Views
5K
  • · Replies 24 ·
Replies
24
Views
3K
Replies
1
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K