The results of my mixture design on Alka Seltzer rockets are shown in the graph, which reveals that the flight time in centiseconds (hundredths) lengthened as the proportion of air-to-water increased (p<0.01 for linear mixture model with no significant lack of fit). The predictive equation in terms of real components (fraction of actual space within the film canister) is:
Flight time (seconds) = 1.24Water+1.95Air
For example, a container filled half way with water before dropping in the Alka Seltzer can be expected to propel the lid for 1.59 seconds (159 centiseconds) of flight time (= 1.24×0.5 + 1.95×0.5).
Give this a try and tell me how close you come to this outcome. I guarantee that you will flip your lid. However, be careful — you’d best wear goggles. I can imagine my mother catching wind of me doing something like this and yelling “that thing will poke your eye out!”