Re: [Phys-l] Weightless (running around in circles)

[John Mallinckrodt <ajm@csupomona.edu>]

On Nov 24, 2006, at 9:01 AM, Bob LaMontagne wrote:

> ... what is the weight of a frog floating just under the surface of  
> a pond. If you remember "Bob's Rules" that I set up a few hundred  
> postings ago, the weight is what a scale glued to the frog's feet  
> would read.
>
> Since the scale probably won't float, it might actually give a  
> negative reading, depending on its construction. Those on the list  
> who insist on using weight as mg would then have to attribute a  
> negative mass to the frog - sort of an "anti-frog".

But YOU were the one who proposed the silly idea of letting "weight"  
be the reading on that scale.  Don't blame US if it gives crazy  
results!  ;-)

By my definition of weight, floating (i.e. "remaining at rest") under  
water or under the influence of magnetic or any other kind of  
noninertial force has no effect on the weight of the frog.  It  
certainly doesn't have any effect on the reading of an ideal  
accelerometer.


John Mallinckrodt

Professor of Physics, Cal Poly Pomona
<http://www.csupomona.edu/~ajm>

and

Lead Guitarist, Out-Laws of Physics
<http://outlawsofphysics.com>