Recent content by pmclough

Very nice proof.

I agree. Should any principle in this collection of principles be independent of the others (i.e. should the collection of principles be as small as possible)?

If you look at the paper you will see that gravity and the conservation of energy are assumptions that are both implied in the statement of Theorem 1. If you want to replace the gravity assumption with a more general assumption about forces that is fine but Theorem 1 would then need to be...

It seems the proof in the paper could be extended to include the modified lever law that mfb proposed above. The law of the lever would then become a simple corollary to this. I think this may cover the concerns you raised about misleading students.

I agree.

I agree that it is the forces and not their origin that counts. I am referring to Theorem 1 in the paper I referenced. Theorem 1 does not hold outside of a constant force field (please note this does not imply that the lever no longer works there). I thought the paper may have some...

The law of the lever (i.e. Theorem 1 from the paper here: http://www.math.csusb.edu/faculty/pmclough/LP.pdf) does not hold outside a constant force field.

True, however, the law of the lever (i.e. Theorem 1 from the paper here: http://www.math.csusb.edu/faculty/pmclough/LP.pdf) does not hold.

It would seem that if I removed gravity then any two masses placed anywhere on the lever would balance the lever.

I agree that what we choose to take as our axioms is quite arbitrary. I chose to prove the law of the lever by taking gravity and the conservation of energy as the axioms for the following reasons: 1.) Gravity and the conservation of energy are both topics that are covered in a beginning...

I am referring to the Theorem 1 from the paper here: http://www.math.csusb.edu/faculty/pmclough/LP.pdf.

Thanks for the example. However, outside of a constant force field the law of the lever does not hold.

If I understand you correctly, it seems that you are suggesting that the conservation of energy notion is dependent on the law of the lever. If this is so then I would appreciate if you could please explain how you came to this conclusion.

Could you please explain what you mean by a lever working without the help of gravity.

The law of the lever being a simple consequence of gravity and the conservation of energy I thought maybe of some value to physics education (some students find the lever mysterious for example see: True Explanation of a Lever...please. ). Maybe I am mistaken but I was under the impression that...