Re: Orbital Kinetic Energy

[Bob Sciamanda <trebor@VELOCITY.NET>]

Brian,
Your proposition is not true for any and all circular orbits.
It is true for the circular orbit maintained by an inverse square central
force (eg: gravitation).  This  force law must be invoked, in some fashion
(eg, through the potential), to prove the proposition.

Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
http://www.velocity.net/~trebor
trebor@velocity.net
----- Original Message -----
From: "Brian Blais" <bblais@BRYANT.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Monday, February 02, 2004 8:04 PM
Subject: Orbital Kinetic Energy


> Hello,
>
> I was wondering if anyone knew of a calculation showing that the kinetic
> energy of an object in a circular orbit is equal to half of the potential
> energy, where the calculation does *not* use acceleration or force at all.
Is
> there an argument for this based purely on energy concepts?  It occurred
to me
> that there should be, but I can't think of it.
>
>            thanks,
>
>             Brian Blais
>
> -----------------
>
>             bblais@bryant.edu
>             web.bryant.edu/~bblais