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  1. #1
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    help

    Please help.

    A car is traveling at 27mph. if its tires have a diameter of 28in how fast are the cars tires turning? express the answer in revolutions per minute.
    Last edited by mr fantastic; April 27th 2009 at 08:33 PM. Reason: Moved from original thread
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  2. #2
    Member SengNee's Avatar
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    Quote Originally Posted by donnyB View Post
    Please help.

    A car is traveling at 27mph. if its tires have a diameter of 28in how fast are the cars tires turning? express the answer in revolutions per minute.
    1)
    Find how far the car travelled in a minute, then divide by circumference of the tyre.

    2)
    v=r\omega
    \omega =2\pi f
    f=?
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  3. #3
    MHF Contributor

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    Another way to do that: find the circumference of the tire and divide into 27 miles. One rotation of the tire will cover a distance equal to the circumference of the tire. That will give the number of rotations per hour so multiply by 60 min/hour.
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