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Homework Help: Tangentail Acceleration

  1. Sep 28, 2011 #1
    1. The problem statement, all variables and given/known data
    A 3.0-cm diameter crankshaft that is initially rotating at 2500 rpm comes to a halt in 1.5 s. What is the tangential acceleration of a point on the surface of the crankshaft? How many revolutions does the crankshaft make as it comes to a stop?

    2. Relevant equations

    at = Dv/Dt

    3. The attempt at a solution

    honestly I am really stuck on this because the only formula that I can find is this one. Any ideas on where to head with it?
  2. jcsd
  3. Sep 29, 2011 #2
    For linear motion we have,

    v = v_o + a*t

    For rotational motion we have,

    thetadot = thetadot_o + thetadoubledot*t

    thetadot = d theta/dt thetadoubledot = d^2 theta/dt^2

    You know thetadot at t = o and you know thetadot at t = 1.5 seconds, solve for thetadoubledot
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