Re: [Phys-l] Statics conundrum

[Ken Fox <physicsfox23@gmail.com>]

I think there is no unique solution for this. The experiment you cite can
have many results depending on how the forces are applied. With the three
men, my personal experience tells me that as we carry such a load, the
forces vary as we move along the ground. We can all apply different forces
and still have the beam in equilibrium.

I am thinking of your experiment. A beam resting on three scales. If a slip
of paper is placed at one contact point, I suspect the three readings will
readjust. If the three men are all of different height......

I'll be interested in other's responses

Ken fox

On Sun, Mar 14, 2010 at 3:02 PM, Bob Sciamanda <treborsci@verizon.net>wrote:

> The two equilibrium equations are insufficient to solve for the values of
> the three unknons, F1 F2 and F3.
>
> The three man experiment can be performed and the forces measured (even
> with added loads on the beam). They ARE physically determined.
>  How does one analytically predict this result?
>
> Please discuss. Is it the perfect rigidity which must be relaxed? Why?
> How explain this to the curious student? (and to me)