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Homework Help: Finding Tangential Acceleration

  1. Oct 31, 2004 #1
    The flywheel of a steam engine runs with a constant angular speed of 425 rev/min. When steam is shut off, the friction of the bearings stops the wheel in 1.7 h.

    At the instant the flywheel is turning at 75 rev/min, what is the tangential component of the linear acceleration of a flywheel particle that is 50 cm from the axis of rotation?

    I know the equation to use is At=(alpha)r, where alpha is dw/dt. In this case I'm not sure how to compute the alpha and I'm sure it's just a simple point that I am missing.
     
  2. jcsd
  3. Oct 31, 2004 #2
    first change the 1.7 hours to seconds, then the 425 rev/min to rad/s

    then:

    [tex]\alpha=\frac{d\omega}{dt}[/tex]

    [tex]\alpha dt=d\omega[/tex]

    [tex]\int_{0}^{t}\alpha dt=\int_{\omega}^{0}d\omega[/tex]
     
  4. Oct 31, 2004 #3

    Doc Al

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    Staff: Mentor

    Use simple kinematics to find alpha: [itex]\alpha = \Delta \omega/\Delta t[/itex]. (Take care with your units, as Spectre5 advises.)
     
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