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Homework Help: Average current speed

  1. Jun 29, 2008 #1
    Ocean currents (miles/hr) at a certain location are given below

    Time of day: Speed mph:
    8:00 am 17
    8:10 am 20
    8:20 am 22
    8:30 am 21
    8:40 am 17

    How can I estimate the average river current speed from 8:00 am to 8:40 am using the trapezoidal rule? I tried but I got a huge number.
  2. jcsd
  3. Jun 30, 2008 #2


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    Homework Helper

    What exactly did you do? Did you draw out the speed-time graph of these points and then attempt to find the area underneath after connecting all the dots?
  4. Jun 30, 2008 #3
    I converted 8:40 into hours so 40/60=2/3
    Then I supposed 0 to be 8:00, so the equation I had was integral sign 0 to 2/3 S(t) dt.
    Then using the data in the chart: (17+2(20)+2(22)+2(21)+17)
    Then I multiplied that sum by 1/(b-a) to get the average, and I got a number in the hundreds.
    Last edited: Jun 30, 2008
  5. Jun 30, 2008 #4
    nvm i got it
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