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What is the significance of sqrt{2gh} ?

  1. Apr 22, 2010 #1
    Hi, I'm not sure how to word my question, so I will just state it upfront.

    What is the importance of [tex]\upsilon[/tex] = [tex]\sqrt{2gh}[/tex] in physics?

    I've seen it in escape velocity problems, though with an R instead of h. I've seen it with conservation of momentum applications, and it's similar to PE = mgh. Yesterday my professor was discussing Bernoulli's equation and this equation came up again.

    I was just wondering how it can be applied to so many different situations...
  2. jcsd
  3. Apr 22, 2010 #2


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    Welcome to PF!

    Hi acspin! Welcome to PF! :smile:

    (have a square-root: √ :wink:)

    It's because v2 is KE per mass.

    Whenever KE + PE =constant, you'll have equations involving v2 = PE/m, which in some cases is gh.

    As to Bernouli's equation, that's just conservation of energy applied to a fluid, and both KE and PE appear in it. :smile:
  4. Apr 23, 2010 #3
    When acceleration is constant, say along the x-axis, then it is necessarily true that

    v^2=2ax. (where v at time t=0 is zero).
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