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Homework Help: A wheel rotates with a constant angular acceleration of 3.30 rad/s2.

  1. Mar 4, 2012 #1
    A wheel rotates with a constant angular acceleration of 3.30 rad/s2. Assume the angular speed of the wheel is 2.45 rad/s at ti = 0.
    (a) Through what angle does the wheel rotate between t = 0 and t = 2.00 s? Give your answer in radians and revolutions.
    (b) What is the angular speed of the wheel at t = 2.00 s?

    Answers: a) 11.50 rad and 1.83 rev
    b) 9.05 rad/s

    Use the values from above to help you work this exercise.
    (a) Find the angle through which the wheel rotates between t = 2.00 s and t = 3.00 s.

    I understood the first part and got the correct answers, however, I have tried this problem a few times and came up the wrong answer.... Here are my attempts with wrong answers:

    (2.45rad/s)(3.00s) + 1/2(3.30rad/s^2)(3.00s)^2 = 22.2rad (wrong)
    AND
    (9.05rad/s)(3.00s) + 1/2(3.30rad/s^s)(3.00s)^2 = 42rad (wrong again)

    Can someone tell me where I am doing this equation incorrectly? I thought on the second attempt I was spot on, but I'm not.

    Thanks!
     
  2. jcsd
  3. Mar 4, 2012 #2

    tiny-tim

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    Homework Helper

    Welcome to PF!

    Hi KTANNE! Welcome to PF! :smile:
    erm :redface:

    2 seconds ! :cry:
     
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