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    The formula for angular momentum about some axis is L=I \omega where I is the moment of inertia about the same axis, and \omega is the angular speed.

    So here it's just finding I, which is fine, I just placed a circle on the xy-plane at the origin and determined \displaystyle I = \frac{M}{\pi a^2} \int \int x^2 .dx dy = \dfrac{Ma^2}{4} over the region x^2+y^2 \leq a^2.

    So the angular momentum is just L=\dfrac{Ma^2}{4} \omega but the one-liner answer reference says \dfrac{Ma^2}{2} \omega instead.

    Is this a typo on the lecturer's part, or is there a point where I was supposed to multiply by 2?
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    (Original post by RDKGames)

    Is this a typo on the lecturer's part, or is there a point where I was supposed to multiply by 2?
    It's not a typo - you've considered a disc, rather than a circle/hoop.

    Edit: Misread the question myself initially.
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    (Original post by ghostwalker)
    It's not a typo - you've considered a disc, rather than a circle/hoop.

    Edit: Misread the question myself initially.
    Ah goodness, thanks :lol:
 
 
 
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