On 21/01/2013 jrc wrote:
>Thanks also for the wikipedia reference where i found i did at least get
>the FF calc correct; and as P noted, the elongation of the rope is not
>relevant as the FF is the pre stress calculation.
>
>As i indicated in my note, my force calculations were an approximation,
>i admit, for simplicity, and were given primarily for relative purposes
>but also to show there are severe forces able to be generated even in 'small'
>falls.
>
>Re the force calc; the energy in the fall would be mgh, this energy being
>absorbed by the stretching rope and resulting in a force along the distance
>it stretched,(which would be proportional to the length of rope deployed,
>not the length of rope itself (as i wrongly calculated giving rise to
>the mgh / r calc where it should have been mgh / (r x%elongation) (assuming
>linear elongation in the foregoing)-sorry for the confusion).
>
I think I've been misunderstood, whilst yes elongation has nothing to do with fall factor, it is a HUGE proportion of the force calculation ... but not: "mgh / (r x%elongation)"...
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