Solution 7


The height rise due to surface tension can be usually calculated using the fact that the drop in P on crossing a spherical meniscus of radius R is 2T/R...

But what if you don't know R..or what if the meniscus is not spherical???

You can always calculate the rise using the fact that the weight of water in the capillary is supported entirely by the forces of Surface Tension.

We have:T(2pi*b)+T(2pi*a)=H(pho)(pi(b^2)-pi(a^2))
weight of water

You can calculate H...you can also enlarge the img. by clicking on it!

6 comments:

  1. KapilFebruary 25, 2010 at 6:33 PM

    so is it right to say that R effective in this case will be (b-a)

    ReplyDelete
  2. AnujFebruary 25, 2010 at 8:59 PM

    maybe...i won't comment...

    ReplyDelete
  3. ♥◘○µ╦┬░Γ╪╬└↑φΦ╫╛◙«½╣↔⌐☺♠♦♣◘○February 25, 2010 at 11:06 PM

    where is g ,acceleration due to gravity in the answer

    ReplyDelete
  4. ♥◘○µ╦┬░Γ╪╬└↑φΦ╫╛◙«½╣↔⌐☺♠♦♣◘○February 25, 2010 at 11:10 PM

    SIR YOU MISS IT IN THE SOLUTION

    ReplyDelete
  5. ♥◘○µ╦┬░Γ╪╬└↑φΦ╫╛◙«½╣↔⌐☺♠♦♣◘○February 26, 2010 at 8:11 PM

    this method is only used for cylindrical capillaries

    ReplyDelete
  6. ♥◘○µ╦┬░Γ╪╬└↑φΦ╫╛◙«½╣↔⌐☺♠♦♣◘○March 1, 2010 at 10:24 PM

    SIR PLEASE SOLVE THE PROBLEM GIVEN BELOW PLEASE!! A child of mass m sits in a swing of negligible mass suspended by a rope of length l. Assume that the dimensions of the child are negligible compared with 1.
    His father pulls the child back until the rope makes an angle of one radian with vertical, then pushes with a force F=mg along the arc of the circle releasing at the vertical :
    a) How high up will the swing go?
    b) How long did the father push?

    ans:(a) theta=63degree above horizon (b) t=1.52(l/g)^1/2

    ReplyDelete

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