1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: What is the wave speed in the bridge?

  1. Dec 9, 2015 #1
    1. The problem statement, all variables and given/known data
    A certain pedestrian bridge in England resonates like a string fixed at both ends. If the bridge is 73.0 m long and its fundamental resonance is at 0.600 Hz, what is the wave speed in the bridge?

    2. Relevant equations
    Velocity = (frequency)(wavelength)

    3. The attempt at a solution

    wavelength = 73.0 m
    frequency = .600 Hz
    velocity = find it

    v = (.600)(73.0)
    v = 43.4 = 44 m/s

    I got this wrong on my hw, I thought this was how to do it? Could someone please show me what I am doing wrong?
    Thank you for your help
  2. jcsd
  3. Dec 9, 2015 #2
    Note that the fundamental resonance is not the same thing as frequency.
  4. Dec 9, 2015 #3
    Multiply by 2.

    The "fundamental resonance" is when the bridge is resonating at only half a wavelength. To correct for this to find the velocity, multiply the length of the bridge by 2.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted