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Homework Help: Angular momentum and orbital angular momentum problems

  1. Feb 4, 2005 #1
    1. A proton of mass rotates with an angular speed of 2*10^6 rad/s in a circle of radius 0.8m in a cyclotron. What is the orbital angular momentum of the proton?

    2.An object's angular momentum changes by 10Kgm/s^2. What magnitude average torque acted on this object?

    3. A pulsar which emits radio waves 642 times per second has a mass of 2*10^30 kg and has a radius of only 15km.
    a) What is the linear speed of a point on the equator of this pulsar? Ignore relativistic effects.
    b) If our sun, with mass 2*10^30 kg and radius 7*10^5 km had the same angular momentum as this pulsar, approximately what would its rotational period be?

    BTW, how do I upload an avatar to my profile? I tried in the CP but I didn't find any option that would allow me to do so.
    Last edited: Feb 4, 2005
  2. jcsd
  3. Feb 4, 2005 #2


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  4. Feb 5, 2005 #3
    I understand what you mean by your post, but I have little to work with, since we are not having these topics in our physics class, this is independent study for the science league. Let's see, I have [tex]I=2/5MR^2[/tex] , I also have [tex]\omega=v/r[/tex]

    I think 3a is like this: Ok, I think I have 3a. it is rotating at [tex](642rev/s)(2\pi rad/rev)(15000m)=V[/tex]

    Besides this, I have no idea as to what to do next.
    Last edited: Feb 5, 2005
  5. Feb 5, 2005 #4
    Ok, I think I've got question # 1. Is orbital angular momentum =angular velocity*radius^2 ?
    Last edited: Feb 5, 2005
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