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Homework Help: A Rotating Pulsar

  1. Oct 26, 2005 #1
    A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio pulse for each rotation of the star. The period T of rotation is found by measuring the time between pulses. The pulsar in the Crab nebula has a period of rotation of T=.033s that is increasing at the rate of 1.26 x 10^-5 s/y

    a)What is the pulsar's angular acceleration?
    I know that T=2pi/w when omega is constant. Does it make sense to that that T(t)=2pi/w(t) ? If this is correct then I can get the answer, but even if it is correct I'm not sure why it works.
  2. jcsd
  3. Oct 26, 2005 #2


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    Gold Member

    I can't do the math. Just remember that the beams are emitted from the magnetic poles of the star, so you can expect that once in a while the orientation will be such that we receive two pulses per revolution. I don't know if any currently known ones are like that, though.
  4. Oct 27, 2005 #3
    Judging by the context of the problem this is irrelevant.
  5. Oct 27, 2005 #4

    Doc Al

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    Staff: Mentor

    Makes sense to me. Note that the rate of change of the period is so slow that for all practical purposes the angular speed hardly changes during one revolution.
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