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Homework Help: A bicycle with tires 70 cm in diameter is traveling along a road at 25 km/hr. What is

  1. Feb 21, 2012 #1
    1. The problem statement, all variables and given/known data
    A bicycle with tires 70 cm in diameter is traveling along a road at 25 km/hr. What is the angular velocity in radians per second?
    (the answer given in the textbook is 19.8 radians per second)

    2. Relevant equations
    A= 1/2r^2 ∅
    l = (radius)(central angle)


    3. The attempt at a solution
    Nvm I figured it out,

    You first convert 25 km/h into cm/sec

    25,000,00/60/60 = 694.5
    Then, we go 2pi * 35 which gives us 219.8
    We then divide 694/219.8

    Which gives us 3.16

    We multiply 3.16 with 2pi

    And get 19.8 radians per second.
     
    Last edited: Feb 21, 2012
  2. jcsd
  3. Feb 21, 2012 #2

    tiny-tim

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    Science Advisor
    Homework Helper

    Hi Daaniyaal! :smile:

    That's correct, but why did you divide by π and then multiply by it again later? :redface:

    Using the standard formula v = rω is much easier! :smile:
     
  4. Feb 25, 2012 #3
    Re: A bicycle with tires 70 cm in diameter is traveling along a road at 25 km/hr. Wha

    Oh! Thanks! I didn't know the formula when I was doing this question, so I had to think it out.
     
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