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Homework Help: Average Speed

  1. May 23, 2007 #1
    A person travels by car from one city to another with different constant speeds between pairs of cities. She drives for 15.0 min at 65.0 km/h, 20.0 min at 75.0 km/h and 60.0 min at 40.0 km/h, and spends 15.0 min eating lunch and buying gas.

    Determine the average speed for the trip.

    I know average speed is total distance/total time but I am confused as to how to get the total distance. For the total time I added 15+20+60+15 and got 110 minutes. Would displacement play a part in this problem?
  2. jcsd
  3. May 23, 2007 #2


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