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: Damped Oscillations?

  1. Oct 21, 2008 #1
    1. The problem statement, all variables and given/known data

    Marie observes damped oscillations of a glider on an air track. She observed that the amplitude decreased to 50% of its original value after 10 seconds. What is the decay constant for the motion of the glider?


    2. Relevant equations



    3. The attempt at a solution

    It seems the equation including the decay constant (involving the displacement, amplitude, angular frequency, and time) seems a little overcomplicated, considering the information given for this particular example.

    However, I do know that if the motion of the damped glider is plotted, then the decay constant τ can be derived from the equation τ = -log e/slope. From the information given, I know that the graph will be of an exponential function, but how do I know what the slope of it would be given a 50% reduction in 10 seconds? Please help!
     
  2. jcsd
  3. Oct 21, 2008 #2

    LowlyPion

    User Avatar
    Homework Helper

    Won't the equation be proportional then to e(-kt) ?

    Doesn't that mean then that e(-k*10) = 1/2 ?

    What happens if you then take the natural log of both sides?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook