Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

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



On Nov 24, 2006, at 2:31 PM, Jeffrey Schnick wrote:

Suppose I established a coordinate system and took some position vs. time measurements on the object that has the accelerometer attached to it. Further suppose that, from that data, I determined the acceleration of the object, call it r double dot, relative to the established coordinate system.

O.K. so far.

I understand r double dot to be the what NIST calls "the local acceleration of free fall in that reference frame."

? I sure don't follow that. I would agree with you if the object actually WAS in free fall, but I didn't see that specified. Maybe you simply forgot to say so?

Is the NIST definition of weight just how hard and which way I would have to
push on the object to make its accelerometer reading be r double dot?

Assuming the object was in free fall when you measured r double dot, I think that's right.

John Mallinckrodt

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

and

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