1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Angular acceleration of a pulsar

  1. Mar 15, 2007 #1
    A pulsar is a rapidly rotating neutron star that emits radio pulses with precise synchronization, there being one such pulse for each rotation of the star. The period T of rotation is found by measuring the time between pulses. At present, the pulsar in the central region of the Crab nebula has a period of rotation of T = 0.19000000 s, and this is observed to be increasing at the rate of 0.00000380 s/y.

    I found the angular velocity to be 33.07 rad/s, I found this by 1/T*2PI

    Now I need to solve the angular velocity. I tried using the rotational kinematic equation:
    Wf = Wi + alpha * t

    Wf = angular velocity final
    Wi = angular velocity initial
    alpha = angular acceleration
    t = time

    Since the period of rotation is increasing by 0.00000380 s/y I added this to 0.19 and then found the Wf by take 1/.19000380 *2PI

    I used the angular velocity that I already solved for Wi, the 33.07 rad/s

    then for the time, it would be 1 year right? But does this need to be in seconds?

    So I plugged these into the equation and solved for alpha

    (Wf - Wi)/t = alpha
    (33.068rad/s-33.069rad/s)/31556926s = -3.1689x10^-11 rad/s^2

    But this is not the correct answer. Any advice?
  2. jcsd
  3. Mar 15, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Your error is in rounding off your values for W. Use many more significant figures in your calculator and you get a better estimate for the change in W.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Angular acceleration of a pulsar
  1. Angular acceleration! (Replies: 2)