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Help! I've tried for 10+ hours

  1. Sep 23, 2003 #1
    I've tried question #1 on here:

    for the past 10 hours, i have achieved getting something relatively close, but i cannot do the algebra to prove t=cosh^(-1) etc etc...

    has anyone done this problem in the past, i know nitrus has a similar one, and i have talked to him, but it was of no use.

    please help me, it is very appreciated.

  2. jcsd
  3. Sep 23, 2003 #2


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    Science Advisor

    There is a time integral and a distance integral. Did you get those? They are each of the form of the 2 integrals given as hints. Combine and you get

    sqrt(k g sin(theta)) t =

    (1/2) ln((1+sqrt(Q))/(1-sqrt(Q)))


    Q = 1 - exp(-2 k d)

    The big thing with the ln in it is actually equal to


    though it is not obvious. So you are done.
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