Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: New troubles hahah

  1. Oct 8, 2006 #1
    we finally got that question, it took us some time but we missed a minus sign!!!!! hahah stupid little mistakes, the ones we are working on now are
    given the amplitude of a damped harmonic oscillator drops to 1/e of its inital value after n complete cycles show the ratio of oscillation to the period of the sam oscillator with no damping is

    T damped/ T undamped = (1 + 1/(4pi^2 n^2) ^(1/2)

    i got the auxillary parts where T undamped equals 4pi squared/q^2 where q is 2pi n , and T damped is 4pi ^2n^2 + c2pi n/m somethings not working because i get the wrong stuff on the bottom and c2pi n/m has to equal 1? or rearranging it i get square root ((cn2 (pi))/k + 1) equals Td/T so cn2 pi /k has to somehow equal 1/(4pi^2n^2)

    for the second problem the terminal speed of a freely fallin ball is v when the ball is supported by a light elastic spring the spring stretches an amount x, show the natural frequiecy is

    w damped = sqare root ( g/x-g^2 / 4v^2)

    i know how to prove w undamped equals squareroot (g/x) that is easy

    for this one i am getting confused with the question from the time when it is accelerating to when it hits terminal speed and doesnt accelerate, do i have to integrate at all or set up two parts to the problem one with acceleration and one without? because how do i know if it hits terminal speed before it stretches the spring to the max x?
  2. jcsd
  3. Oct 8, 2006 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    Why are you starting a new thread for this same problem? Stick to your https://www.physicsforums.com/showthread.php?t=134975" or you will have us even more confused than we normally are.

    Last edited by a moderator: Apr 22, 2017
  4. Oct 8, 2006 #3
    iunno ive never used this site before i dont know what to do
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook