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Homework Help: Make a graph comparing velocity

  1. Oct 2, 2006 #1
    I currently have two problems left that I have to complete for physics, but I can't seem to figure out how to solve them.
    1. A person takes a trip, driving with a constant speed of 89.5 km/h except for a 22.0-min rest stop. If the person's average speed is 77.8 km/h, how much time is spent on the trip and how far does the person travel?

    (NOTE: I do not need the answer, I just need to know how to solve it)
    2. Make a graph comparing velocity (velocity-time graph, 2 curves)
    (box=car, circle=big rolling marble/ball/object)

    http://img83.imageshack.us/img83/4576/problemte3.gif [Broken]
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Oct 2, 2006 #2
    They give us an average velocity of 77.8 km/h. We know that average velocity is (change in distance)/(change in time). so start from there

    77.8 = (change in distance)/(change in time)

    the change in distance is 89.5 km/h * X (x = some number of hours that he spent driving). the change in time is X + (22/60) (the time he spent driving + the break he took). since the velocities are given in hours, the break should be converted from minutes into hours.

    so that gives...

    77.8 km/h = (89.5 km/h)X / (X+(22/60))
    x = 2.44 hours

    to get the distance traveled simply take 89.5*x to get 218.2 km
  4. Oct 2, 2006 #3
    Wow, its so simple. Thanks for your help, BishopUser.
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