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View Poll Results: Calculate average speed

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  • 12 mph

    3 4.48%
  • 13.3 mph

    48 71.64%
  • 15 mph

    13 19.40%
  • 17.67 mph

    2 2.99%
  • something else

    1 1.49%
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  1. #1
    Around now and then DnvrFox's Avatar
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    Just for Fun - Calculate Average Speed

    Just for FUN, please. Most of you have done this before, others may find it new and perhaps surprising. Anyway, it's time to revisit calculating average speed.

    OK - if one goes 10 miles at 20 miles per hour and 10 miles at 10 miles per hour, what is the average speed?

    Please check your answer above.

    Again, just for FUN
    Last edited by DnvrFox; 07-07-11 at 07:55 PM.
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  2. #2
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    The BF average is 22 mph because they don't count the stops and it was windy.

  3. #3
    Around now and then DnvrFox's Avatar
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    Quote Originally Posted by Dan The Man View Post
    The BF average is 22 mph because they don't count the stops and it was windy.
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  4. #4
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    Quote Originally Posted by Dan The Man View Post
    The BF average is 22 mph because they don't count the stops and it was windy.
    ...and it was ridden on an old steel bike, and the brakes were rubbing, and the tires weren't properly inflated, and it was too hot, too humid, too cold and too dry all at once (but only in the road forum).

  5. #5
    Senior Member Allegheny Jet's Avatar
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    Is this a SAT test? Do trains still leave Denver @ .....
    oldschool areodynamic brick

  6. #6
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    Is there a headwind or any hills?

  7. #7
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    If you do the math, you will find that if you climb a 5 mile hill slowly, and descend the other side (5 miles) very fast, your average speed is not your speed ascending plus your speed descending, divided by 2.

  8. #8
    Around now and then DnvrFox's Avatar
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    Quote Originally Posted by kenji666 View Post
    If you do the math, you will find that if you climb a 5 mile hill slowly, and descend the other side (5 miles) very fast, your average speed is not your speed ascending plus your speed descending, divided by 2.
    You're supposed to do MATH??
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  9. #9
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    Or you can just count on your fingers and toes.

  10. #10
    Around now and then DnvrFox's Avatar
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    Quote Originally Posted by kenji666 View Post
    Or you can just count on your fingers and toes.
    That would get me to 22! That's a great average speed.
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  11. #11
    Icantre Member stonefree's Avatar
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    Oh, I thought you meant what was our individual average speed. 22 is about my top speed down a wimpy underpass.
    "If we don't change direction, we will end up exactly where we are headed."

  12. #12
    Around now and then DnvrFox's Avatar
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    Quote Originally Posted by Allegheny Jet View Post
    Is this a SAT test? Do trains still leave Denver @ .....
    Looks like most folks are going to make it into college, but only into colleges west of Denver.
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  13. #13
    Senior Member ?? Beverly's Avatar
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    Quote Originally Posted by kenji666 View Post
    Or you can just count on your fingers and toes.
    Or I would just look at my Garmin and let it do the math for me

    Math was never my favorite subject........
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  14. #14
    Senior Member Retro Grouch's Avatar
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    I find that I go much faster and farther when I ride a bike that doesn't have a computer and estimate speed and distance.

  15. #15
    Icantre Member stonefree's Avatar
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    Two degrees is enough for me. Math is boring. Tunes rule. There's nothing west of Denver but fruits and nuts.
    "If we don't change direction, we will end up exactly where we are headed."

  16. #16
    Senior Member bigbadwullf's Avatar
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    Try figuring out a golf handicap index some time.

    http://tickers.TickerFactory.com/ezt...S/exercise.png

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  17. #17
    Senior Member Looigi's Avatar
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    hint: (a+b)/(c+d) not equal to (a/c) + (b/d)

  18. #18
    Senior Member EsoxLucius's Avatar
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    20/1.5

  19. #19
    Oldie but Newbie duceditor's Avatar
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    Quote Originally Posted by esoxlucius View Post
    20/1.5
    :d

  20. #20
    Around now and then DnvrFox's Avatar
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    Quote Originally Posted by EsoxLucius View Post
    20/1.5
    There's always someone in the crowd who can't keep a secret
    DnvrFox - still bicycling, swimming, walking and weight lifting at 74yo is participating a bit in BFN 50+.

  21. #21
    just keep riding BluesDawg's Avatar
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    Quote Originally Posted by DnvrFox View Post
    There's always someone in the crowd who can't keep a secret
    Probably that same one in every class in school who would raise his hand after every question saying "me, me, call on me..."
    The more you ride your bike, the less your ass will hurt.

  22. #22
    Starting over CraigB's Avatar
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    Quote Originally Posted by Retro Grouch View Post
    I find that I go much faster and farther when I ride a bike that doesn't have a computer and estimate speed and distance.
    Agreed. Computers have a terrible effect on performance. Must be all that magnetic drag.
    Craig in Indy

  23. #23
    Pedal pusher... alicestrong's Avatar
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    My average speed on the street is pretty slow, much faster on the San Gabriel River Trail, but I'm not sure many have the luxury of an almost flat, nearly empty smooth trail with (almost) no stops on which to measure their speed...
    Last edited by alicestrong; 07-08-11 at 04:58 PM.
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  24. #24
    Senior Member gcottay's Avatar
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    You probably want the 4th grade arithmetic answer but I like to wander a bit. Okay, maybe more than a bit. Going ten miles can easily involve an extra ten miles of "Wonder what might be down that road/street/trail" and given that I never ride on a plane surface we'd have to get into various schemes for describing the topology of non-linear surfaces.
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  25. #25
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by DnvrFox View Post
    Just for FUN, please. Most of you have done this before, others may find it new and perhaps surprising. Anyway, it's time to revisit calculating average speed.

    OK - if one goes 10 miles at 20 miles per hour and 10 miles at 10 miles per hour, what is the average speed?

    Please check your answer above.

    Again, just for FUN
    Vavg is equal to total distance divided by total time, assuming all time was spent riding as stated. Total distance is 10 +10 = 20. Total time duration is 10/20 +10/10, or 3/2 hours. Dividing 3/2 into 10, we get a long division problem of 40/3. The answer to that is 13.3 mph, rounded to one decimal place.

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