I have attached a pic which really explains the formula and context of the problem. I'm guessing a gravitational effect passes for physics.... I am trying to convert the formula in (b) below into feet. If I could reproduce the answer with English units, I could move on and apply the formula to other situations, but the multiplicity of English units is really confusing me. The English units I have are; g = 32.17405 x = 3277.972 Next two from my tapes manufacturer, A = 0.003" (but I think it should be 0.034 feet) E = 29,700 KSI M = 0 but could be 20 lbs. Next one again from the manufacturer, m = 0.0102 lbs/ft. l = 3280.84 P(sub)0 = ? but my hundred foot tape would be 23 lbs.