1. The problem statement, all variables and given/known data Hi all, I'm writing an article for a scouting magazine. It is a short column to inform people about the danger of using long -badly supported - horizontal poles. I'd like to compare the situation of using a short beam and a long beam, and then able to tell a rough percentage how much worse the long beam is over the short one. 2. Relevant equations Bending moment (UDL) = WL^2/8 (Kg-mm or Kg-m) Bending moment (point load) = Force x Distance ( This is actually for a horizontal beam with load acting is a point load) (Kg-mm or Kg-m) 3. The attempt at a solution "Image you're building a simple swing. Supports on either side, horizontal pole on top, attach plank with 2 ropes, done! If you made a normal sized swing, using a top pole of 2 meters, you can put Charlie and 3 other friends on it and it'll hold. But if you use a top pole of 4 meters, maybe you can just put Charlie in it." Idea: ASSUME: the relation between the length of the pole and the stress is L^2 Swing with 4 meter pole can hold 1 kid, causing stress 1 kid * 4^2 meters = 16 Swing with 2 meter pole can hold 4 kids, causing stress 4 kids * 2^2 meters = 16 This article will be read by people barely able to do vector math, so I have to keep things easy :) To summarize what I'm looking for: to correct what I put behind ASSUME, with some background info. An article that clarifies it will do as well, I've looked around but couldn't get it clear enough. Thank you very much!