I need a couple of formulas to determine the live and dead load on a stretched cable for a zip line. They are: 1. If a cable of "A" length and "B" weight is stretched from Point "C" to Point "D" with a sag of "Z" percent, and I place a live weight of "E" pounds at distance "F" from point "C" what is the live load on the cable and what is the stress at points "C" and "D". 2. If the Elevation of point "C" is "X" and Point "D" is "X-Y" and the sag in the cable is "Z" , what is the speed of live weight "E" at distance "F" from point "C". I would like these formulas in a form that I can use them with Excel so that I can plug in the variables to get max speed, min speed, max stresses, etc. I want to be able to determine the elevations of the termination points of zip lines in order to get the desired speeds at the end termination point without having the participant stop in the middle. How strong the termination points need to be, how strong the cable must be, for various size zip line lengths.