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Length ratios help

  1. Aug 7, 2006 #1
    a pendulum with the length (1) = 100 cm has a period of T(1).
    What length (2) is needed to increase the period by
    50 s?

    i found out that T(1) = 2.0063s
    then for T(2),length(2) = 162.071m

    i use T = 2pi sqrt(length / gravity)
    i think there is smtg wrong with my calculation

    can smby pls correct me

  2. jcsd
  3. Aug 7, 2006 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Not sure what you did. Instead of a lot of calculation, use ratios:
    [tex]\frac{T_2}{T_1} = \sqrt{\frac{L_2}{L_1}}[/tex]

    Solve for L_2 in terms of L_1.
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