Go Back   Physics Help Forum > High School and Pre-University Physics Help > Thermodynamics and Fluid Mechanics

Thermodynamics and Fluid Mechanics Thermodynamics and Fluid Mechanics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old May 1st 2009, 02:19 PM   #1
Junior Member
 
Join Date: May 2009
Posts: 2
capillary action: mercury depression

hi guys, need some help for this question.

a capillary of unknown internal radius was inserted into a pool of mercury into a pool of mercury. the height of mercury within the capillary was depressed 1.6cm below the free liquid. Calculate the internal diameter of the capillary. For the mercury-air interface on glass, the contact angle is 140 degree. for mercury at 298.15K, density= 13.59g/cm3, surface tension=0.4865Nm-1

im not sure how to go about solving this question. is it the same approach for capillary rise, but in this case it's a depression, which is due to the cohesive force being greater than the adhesive force. for capillary rise, 2 x pi x r x surface tension x cos angle = pi x r2 x h x density x g.
mint is offline   Reply With Quote
Old May 9th 2009, 10:31 PM   #2
Senior Member
 
Join Date: Apr 2008
Location: HK
Posts: 886
I guess the same approach is used. Simply the difference is that the cosine of the contact angle is negative and the distance h should be the distance between the top of meniscus and free liquid water level.

Last edited by werehk; May 9th 2009 at 10:36 PM.
werehk is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Thermodynamics and Fluid Mechanics

Tags
action, capillary, depression, mercury



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Tapering Mercury Barometer praveenbm5 Thermodynamics and Fluid Mechanics 2 Jul 18th 2015 11:57 PM
Young's Equation, Surface Wetting, and the Capillary Effect capillaryQuestions Advanced Thermodynamics 1 Apr 29th 2014 09:39 AM
Final Temperature of mercury pre pt marc Thermodynamics and Fluid Mechanics 1 May 1st 2011 11:44 AM
inclined capillary r.samanta Thermodynamics and Fluid Mechanics 2 Oct 19th 2009 05:07 AM
Liquid flow through capillary tube MathGuru Thermodynamics and Fluid Mechanics 1 Aug 1st 2008 11:56 AM


Facebook Twitter Google+ RSS Feed