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Thread: need a math expert

  1. #1

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    need a math expert

    hello, i have a math question for you.
    If i have a wheel 2" in diameter, and it makes 1 revolution per minute. How many miles per hour is it going? i should really know this one.

    thanx for your help.

  2. #2
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    2Pr is the key to this one. Circumference of wheel is 2*3.1415*2 = 12.566 inches. So it moves 12.566 inches in 1 revolution, which takes 1 minute

    Then change the units into mph and you're there
    Last edited by chrisjk; May 17th, 2001 at 04:32 PM.

  3. #3
    Monday Morning Lunatic parksie's Avatar
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    How big is 2"?
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  4. #4
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    2" = 2 inches

  5. #5
    Monday Morning Lunatic parksie's Avatar
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    Thanks

    Remember speed = distance / time
    I refuse to tie my hands behind my back and hear somebody say "Bend Over, Boy, Because You Have It Coming To You".
    -- Linus Torvalds

  6. #6
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    Originally posted by chrisjk
    2Pr is the key to this one. Circumference of wheel is 2*3.1415*2 = 12.566 inches. So it moves 12.566 inches in 1 revolution, which takes 1 minute

    Then change the units into mph and you're there
    Er... I'm not trying to be picky, but the diameter of the wheel is 2" therefore the radius is 1" therefore it's 2*3.14159 = 6.28318 inches per minute.

    SD
    "I'd rather have a full bottle in front of me than a full frontal lobotomy!"

  7. #7
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    So all we need to know now is how many feet or inches in a mile.

    Anyone know?

    SD
    "I'd rather have a full bottle in front of me than a full frontal lobotomy!"

  8. #8
    Monday Morning Lunatic parksie's Avatar
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    True.
    I refuse to tie my hands behind my back and hear somebody say "Bend Over, Boy, Because You Have It Coming To You".
    -- Linus Torvalds

  9. #9
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    yeah yeah SD, that's why I didn't do Maths Degree!!!

    Cheeky sod

  10. #10
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    Originally posted by SurfDemon
    So all we need to know now is how many feet or inches in a mile.

    Anyone know?SD
    Well 1 mile/minute is 63359.873279999985 inches/minute

  11. #11
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    Mmmm, Chris so using your maths how many inches have you been telling the girls, 'cause I think you might need to half it

    SD
    "I'd rather have a full bottle in front of me than a full frontal lobotomy!"

  12. #12
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    Luckily I've been saying 14". Phew!

  13. #13
    Monday Morning Lunatic parksie's Avatar
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    Phew!
    Probably what they said as well!
    I refuse to tie my hands behind my back and hear somebody say "Bend Over, Boy, Because You Have It Coming To You".
    -- Linus Torvalds

  14. #14
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    "I'd rather have a full bottle in front of me than a full frontal lobotomy!"

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