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Homework Help: Average Speed/Average Velocity Problem

  1. Sep 20, 2004 #1
    I have a physics problem here that I need help solving. I need to figure out how to find the average speed and average velocity of a trip.

    City A to City B is 55 miles with an angle 7.86 degrees west of north.

    City B to City C is 75.5 miles with an angle 25.9 degrees west of north

    City C to City D is 208 miles with an angle of 41.1 degrees west of north

    City D to City E is 98.8 miles with an angle of 5.45 degrees north of west

    ----I take one 10 minute stop to fill up gas.


    Then I return taking a scenic route:

    City E to City F is 89 miles with an angle of 24.1 degrees east of south

    City F to City G is 23.6 miles with an angle of 14.8 degrees east of south

    City G to City H is 194 miles with an angle of 41.2 degrees south of east

    City H to City A is 88.0 miles with an angle of 18.4 degrees south of east

    --------I spend 45 minutes at each city on the way back

    --------Average Speed for entire trip is 53.7 mi/h


    1. what is the average speed and average velocity from City A to City C?

    2. what is the average speed and average velocity from City C to City E?

    3. What is the average speed and average velocity from City E to City A on the return?


    Any help would be greatly appreciated!
     
  2. jcsd
  3. Sep 20, 2004 #2

    arildno

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    Any help might be given if you show some of your own work! :wink:
     
  4. Sep 20, 2004 #3
    Do I break this down into all the x and y components? of each vector?


    Our book uses average speed and average velocty as if they were the same, what is the main difference
     
  5. Sep 20, 2004 #4

    arildno

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    Velocity is a vector quantity; speed is the (scalar) magnitude of that quantity.
     
  6. Sep 20, 2004 #5
    speed = total distance / total time

    velocity = change in displacement/change in time

    r cos angle= x component

    r sin angle= y component

    this is all I know
     
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