Recent content by nna

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    Centre of Mass Independence from Origin for Systems of Particles

    why the center of mass is a unique point whose definition is independent of the reference origin?
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    Proof of Elliptical Motion through R(t) Equation

    I understood what you say, but the only thing I could see was that the ellipse is rotated, but I still don't know how to prove the statement
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    Centre of Mass Independence from Origin for Systems of Particles

    for a system of particles why is centre of mass independent of the origin?
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    Proof of Elliptical Motion through R(t) Equation

    Homework Statement Hi!, can anybody help me with this problem? Proof that the position vector r(t) = A cos \omegat i + B sin (\omegat + \alpha) moves on an ellipse. I understand that the parametric equation for an ellipse is x=a cos t & y=b sin t, but I just can't find any...
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    Deriving dA/dt = \omega x A: Proof for Constant Vector A and Vector \omega

    ok ok thank you so much! it really helps... jaja it was very easy sorry
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    Deriving dA/dt = \omega x A: Proof for Constant Vector A and Vector \omega

    Sorry :( but I don't understand how that helps...
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    Deriving dA/dt = \omega x A: Proof for Constant Vector A and Vector \omega

    I hope somebody can help me.. this is the problem i have to proof that if A is a constant vector then I can write its derivate as dA/dt = \omega x A.. where \omega is a vector, and the "x" is the cross product