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: Test tomorrow please help

  1. Dec 2, 2007 #1
    Test tomorrow...please help!!!!

    1. The problem statement, all variables and given/known data
    A student in a parked car honks the horn, which has a `proper' frequency of 310.00 Hz. An observer in an approaching vehicle measures the frequency of the sound to be 342 Hz. Calculate the speed of the approaching vehicle. Use 340 m/s as the speed of sound in air.

    2. Relevant equations

    3. The attempt at a solution
    Fs = 310 Hz
    Fo = 342 Hz
    Vo = 0 m/s
    V = 340 m/s
    Vs = ?

    I know
    Vs = (Fs - Fo / Fs + Fo) * V
    if the object is going away from the observer
    but how I do calculate if the object is approaching the person?
  2. jcsd
  3. Dec 2, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    You already have a thread open on this same question. Use it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook