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Will the Barometer level change?

  1. Sep 10, 2011 #1
    The problem statement, all variables and given/known data

    The mercury level in the barometer at sea level is recorded to be 76cm.

    So, I was wondering if you use a thinner tube. Will the mercury level change?

    At sea level, the pressure is 1 atm and thus according to the equation, p = hpg, whereby pressure is equal to the height of the mercury multiply by its density multiply by gravitational field strength, a thinner tube does not affect the mercury level and thus, it will not change.

    But, I came across something called capillary action, whereby the height of the mercury level is affected by the radius of the tube.

    So, will the mercury level change?
  2. jcsd
  3. Sep 10, 2011 #2
    In hpg we neglect the effects of surface tension of mercury.so practically the height will change.
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