Re: Human Reaction Time

[Jack Uretsky <jlu@HEP.ANL.GOV>]

        I have done this as a prelude to an exercise on tailgating.
        Hold a penny against the meter stick, so that it falls when
you release the pressure.  Let the subject place a hand on the table,
palm up, about 25 cm from the meter stick (about the distance from
accelerator to brake pedal).
        My experience is that the reaction time to catch the falling
penny (no warning of when the pressure on the penny will be released)
is > 0.3 s.  At 30 mph this is long enough to set up a closing rate
of about 9 mph (4 m/s) while the cars are decelerating.
                                Regards and happy collisions,
                                                Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
                          Mark Twain, <Extract from Eve's Autobiography>

On Wed, 19 Jan 2000, Robert Carlson wrote:

> We just did the drop/catch meter stick experiment and found human reaction
> time to be 0.21 s with a standard deviation of 0.05 s.  I searched the
> internet and found a reference that matched the mean closely, but could not
> find a reference for the standard deviation.  What have others found for this
> experiment?
>
> The data is at the following address if anyone is interested.
>
> http://www.mctc.mnscu.edu/~carlsoro.faculty/physastr/engineer/engr105/tue/tue.
> htm
>
> Bob Carlson