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Re: [Phys-l] Strange fall data



Josh Gates wrote:
/snip/
The problem is: the acceleration always turns out to be >g /snip/

I've had this problem before, demonstrating free fall with high speed video analysis, picket fences, and sonic rangers. The acceleration always turns out to be a bit bigger than g.

Any ideas?

Thanks!
I wander what percentage is represented by "a bit" ??
A camera that runs at 300 fps nominal might be able to capture measurable flicker
from a mains fluorescent tube that is panned across its field of view quite quickly.
The short term stability of the line frequency is better than 2% I believe.
Alternatively, you might take the measured acceleration of a steel ball as
representing the actual local value for g in your area... 9.8 m/s^2 ?? and take
it from there.

Brian W