Solving for Pressure Rise in Manometer with Oil & Mercury

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SUMMARY

The discussion centers on calculating the fluid level rise in a manometer using oil and mercury when the pressure in an air tank increases by 0.72 cm of Hg. The relevant equation used is P = rho * gravity * height, where the density of oil is 0.91 g/cm³ and mercury is 13.6 g/cm³. The user attempted to equate the pressures of oil and mercury but struggled to arrive at the correct height for the oil column, estimating it to be around 10.76 cm, which was deemed incorrect. The correct approach involves understanding the density differences and applying the pressure equation accurately.

PREREQUISITES
  • Understanding of fluid mechanics principles
  • Familiarity with the manometer concept
  • Knowledge of density and its impact on pressure calculations
  • Proficiency in using the equation P = rho * gravity * height
NEXT STEPS
  • Review the principles of hydrostatic pressure in fluids
  • Study the differences in density between various fluids, specifically oil and mercury
  • Practice solving manometer problems with different fluids
  • Explore the implications of pressure changes in closed systems
USEFUL FOR

Students studying fluid mechanics, engineers working with pressure measurement systems, and anyone involved in laboratory experiments using manometers.

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Homework Statement



A manometer using oil (density 0.91 g/cm3) as a fluid is connected to an air tank. Suddenly the pressure in the tank increases by 0.72 cm of Hg. (a) By how much does the fluid level rise in the side of the manometer that is open to the atmosphere? (b) What would your answer be if the manometer used mercury instead?

Homework Equations



P = rho*gravity*height

The Attempt at a Solution


I have looked at several options of solving this problem. None of them make any sense to me. Please help. Thankyou!
 
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The question is asking how high does a column of oil have to be to weigh the same as a 0.72cm column of mercury
 
ok.
so i set the to two pressures equal to each other
so i got P(oil)=P(mercury)
(.91)(980)h = (980)(.72)(13.6)
solved for h, and provided my answer in cm but its not right :\
 
If I'm reaing the question in the same way as you that should be correct (you can ignore 'g' it cancels)
The oil is roughly 15x less dense than mercury - so you should have an answer around 10cm (roughly)
 
yea i got 10.76. Its not right...
 

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