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Homework Help: Angular acceleration of machinery

  1. Jul 23, 2008 #1
    A piece of machinery is spinning at 760rpm . When a brake is applied, its rotation rate drops to 480rpm while it turns through 210 revolutions.

    What is the magnitude of the angular deceleration?

    Answer in Rad/s^2

    Eqn I used:[tex]\omega[/tex]^2=[tex]\omega[/tex]_0_^2+2[tex]\alpha[/tex](change in theta)

    I put 480^2=760^2+2(alpha)210

    I got 3.79e-3...
    what did I do wrong? Ithink its the units, they are very confusing.
  2. jcsd
  3. Jul 23, 2008 #2
    i'd convert the distance to radians, and all the speeds to radians per sec right off the bat. so 760 rpm x 2pi / 60 would give you rad/s for example
  4. Jul 23, 2008 #3
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