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Homework Help: EC Air resistance problem.

  1. Nov 13, 2011 #1
    1. The problem statement, all variables and given/known data

    all information is on picture

    2. Relevant equations

    3. The attempt at a solution
    I read the paper and understood it but when I got to the first question I was really confused. I do not even know what the problem is asking. This problem could give me an A in the class but its confusing the hell out of me. where did the e come from. If anyone can give me any hints or anything I would really appreciate it. I have worked on it for about 2 hours and I cannot figure it out. Please help

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  3. Nov 13, 2011 #2
    I end up with Vx=e^(-Yt) where Y=b\m
    But i don't know where the cosine comes from for part 1
  4. Nov 24, 2011 #3


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    Are you familiar with adding vectors together and with splitting a vector into horizontal and vertical components?
  5. Jan 5, 2012 #4
    for the first part, where

    V,x(t)=V0costheta(e^-gamma(t)) I would search up the true definition of e. I believe it has to do with taking the limit as n->infinity of (1 +r/n)^1/n, but I think I'm wrong. Once you gather this information, think about it's meaning and relate it to this problem to prove that this is true.
  6. Jan 5, 2012 #5
    oops I was close:
    e = limn->infinity (1 + 1/n)^n.
    where lets say you have V0 then V=V0(1+a/n)^nt if P=P0(1+r/n)^nt=P0(e^rt)due to the limit as n approaches infinity.

    Don't quote me on this one, but just try to reason this analysis out to provide a thoughtful proof that makes logical sense.
  7. Jan 5, 2012 #6
    I'd then relate this analysis to euler's method. You know what that is right? I mean I hardly do, but this limit as n approaches infinity seems analogous to euler's method.
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