So, I am writing a textbook on working with bungee in the theatrical, dance and circus industries. This book is focused mostly on the "these are the knots you use and how to tie them; this is how to splice bungee; this is how to make a bungee pack; this is how to put on a bungee harness; this is how you keep this part safe, ect". In the real world of human life and bungee we typically use a load/elongation curve and a rebound curve to calculate out how much and what length of bungee to use for what effect. In large part we do this because these curves easily adapt to the changes in production run of the rubber, heat, humidity and other real-world factors that are a lot harder to deal with in a simple formula. To be clear, the focus in this book will be on making and using elongation and rebound curves to determine what to use, so little to no fear of people getting killed using this. BUT this is a textbook. The publisher wants me to find and in a page or two explain a SIMPLE physics formula for calculating bungee that can be fairly easily explained to students without a physics background (why? To piss off physics and non physics students I am sure...). The three parts of the equation are obviously Freefall (mass * acceleration of gravity over the unstretched length of the cord) Deceleration (energy of the fall taken up by the spring constant of the bungee until it stops the mass) Rebound (built up energy in the spring overcomes the force of gravity and rebounds them upwards) So, does anyone got any resources that might help? Anything that is aimed at middle school age is probably most applicable. Thanks everyone.