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Question on pendulum clocks

  1. Feb 13, 2012 #1
    I hope this is the right place for this kind of question - please forgive me if it isn't.

    I am wondering about the expected effect of acceleration and/or motion on a pendulum clock. It pertains somewhat to relativity theory, but [to my understanding] it is equally a mechanical engineering question.

    If a pendulum clock is put on a train and the train accelerates to an inertial speed, will that clock tick at the same rate as a similar clock left behind in the train station (at rest on earth)? If not, does anyone know by how much it would change?

    Also, if a pendulum clock was built on a train traveling at an inertial speed, such that it didn't undergo acceleration, would it be expected to tick at the same rate as a clock in the train station?

    Am I right in presuming that a pendulum clock would not work in deep space?

    Also, if acceleration is the same as gravity, or at least has the same effect, would a pendulum clock accelerating in deep space start to tick, given the correct orientation?

    Apologies for the glut of questions, it's just something I've been wondering about.
  2. jcsd
  3. Feb 17, 2012 #2


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    Gold Member

    You seem to be basing all of your thinking on a gravity driven pendulum. Torsion spring driven pendulums work just fine when away from the earth. They have been used for years in mechanical time fuzes.
  4. Feb 17, 2012 #3
    thanks OldEngr
  5. Feb 19, 2012 #4


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    Staff: Mentor

    Do not post the same thread in multiple forums.
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