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Homework Help: Solve for t

  1. Mar 26, 2009 #1
    1. The problem statement, all variables and given/known data

    Solve for t

    y = -4Ve^(-t/4) - 4gt + 4V

    2. Relevant equations

    V = Initial Velocity
    g = Gravity
    t = Time

    3. The attempt at a solution

    y = 0 (Physics problem, hitting a golfball and solving for t when y = 0)

    -4V = -4Ve^(-t/4) - 4gt
    V = Ve^(-t/4) + gt
    1 = e^(-t/4) + gt/V
    0 = -t/4 + ln(gt/V)

    Couldn't get further
  2. jcsd
  3. Mar 26, 2009 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Looks good up to here.
    Sorry, no, logarithms don't work that way:
    log(A+B) ≠ log(A) + log(B)​

    The equation
    1 = e^(-t/4) + gt/V​
    can't be solved analytically, and will require a numerical solution. And that would require a value for V; were you given one?

    p.s. welcome to PF.
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