Re: air resistance

[John Mallinckrodt <ajmallinckro@CSUPomona.Edu>]

On Sat, 6 Dec 1997, John Mallinckrodt wrote (or meant to write):

> With do = d at the first time, vo = v at the first time, r = b/m where m =
> mass of falling object, and F_drag = bv^n, I get the following (all in SI
> units) 
>
>  r        n     do       vo      g     rms deviation in d values
> 0.18     0.2   0.608    1.776   9.8             .0009
> 0.023    2.0   0.6078   1.772   9.8             .0007
> 0.0004   5.0   0.6079   1.763   9.8             .0008
>
> The values of the best fit parameters will surely depend to some small
> extent on the numerical method used.  I used a simple "predictor-
> corrector" type method.  I could have obtained marginally better fits by
> allowing g to be a free parameter as well, but that was clearly pushing
> the data too hard.

In fact, I can get an almost equally good fit to the data by simply
assuming a constant drag force leading to a constant acceleration of 9.57
m/s^2 with do = .6081 m and v0 = 1.777 m/s^2. 

John
-----------------------------------------------------------------
 A. John Mallinckrodt      http://www.intranet.csupomona.edu/~ajm
 Professor of Physics    mailto:ajmallinckro@csupomona.edu
 Physics Department       voice:909-869-4054
 Cal Poly Pomona            fax:909-869-5090
 Pomona, CA 91768-4031   office:Building 8, Room 223