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Re: [Phys-L] angular momentum - error

I would like to withdraw this erroneous comment.

Brian Whatcott Altus OK

On 7/21/2014 9:06 PM, brian whatcott wrote:
It would be more reasonable to assert (in my opinion) that for Robert's conditions,
angular momentum is only conserved about an origin at (-inf,0)

Brian Whatcott Altus OK Indianian Territory.

On 7/21/2014 1:04 PM, wrote:
Consider the motion of a ball, free of all forces, to be the constant velocity path: x=a (a constant), and y= vt (v is its constant speed).
Its angular momentum about the origin (0,0) is simply m*a*v, a constant in time. In the same way, Its angular momentum about any fixed point is a constant in time .

Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
-----Original Message----- From: Paul Lulai
Sent: Monday, July 21, 2014 1:36 PM
Subject: [Phys-L] angular momentum

I am finding I have some questions about conservation of angular momentum that I hadn't considered in the past. If I am investigating the angular momentum of a soccer ball about a point, is angular momentum only conserved if the ball is orbiting about the center of a circular path or a foci of an ellipse? Certainly a ball traveling directly west across a field does not have its angular momentum conserved.
I am completely excluding the idea of impulse, torques, and isolated systems at this point. I just found I haven't thought about this aspect before.
Thanks for your thoughts.
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