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Homework Help: Angular momentum space capsule

  1. Oct 16, 2007 #1
    1. The figure shows the rear view of a space capsule that was left rotating about its axis at 6 rev/min after a collision with another capsule. You are the flight controller and have just moments to tell the crew how to stop this rotation before they become ill from the rotation and the situation becomes dangerous. You know they have access to two small jets mounted tangentially, at a distance R = 3 m from the axis, as indicated in the figure. These jets can each eject 29 g/s of gas from each jet with a nozzle velocity of 800 m/s. Determine the length of time these jets must run to stop the rotation. In flight, the moment of inertia of the ship around its axis (assumed constant) is known to be 5800 kg·m2.

    2. omega = alpha(time)
    v = r(omega)
    a = r(alpha)

    3. I dont know where to start on this, my attempts would not be worth posting
  2. jcsd
  3. Dec 22, 2008 #2
    I realise this is a very old thread but I thought this was a good problem and I wanted to practise some LaTeX.

    [Moderator Note] Latex and complete solution removed.
    Last edited by a moderator: Dec 22, 2008
  4. Dec 22, 2008 #3


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    This is indeed a very old thread, but we still do not allow complete solutions to be posted.

    Please don't use the forum to practise your latex skills. Latex image generation (and storage) requires a significant proportion of the server's resources. There are several sites on the internet which do allow you to practise latex or alternatively, you could download the software yourself.
  5. Dec 22, 2008 #4
    First of all, u need to find momentum force M caused by nozzle.
    We have M=dL/dt ( L stands for linear momentum caused by the deflating gas), also dL=mvRdt . So M=mvR=800*29*10^-3=23.2
    Then alpha=M/I=0.012 and so on...
    [Moderator Note] Answer removed
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