I'm writing regarding your misinformation regarding the Pinewood Derby. Although I have never been in the quasimilitary organization that invented the sport, I have learned some basic physics in my art education. One thing I learned (I think it was the first day of Physics 101) is that basic physics deals in an ideal world. You referred to Galileo, who found that heavier objects don't fall faster, but they really do. The reason has to do with what we call in the art world "friction." (You actually touched on it, referring to the feather effect.) You even mentioned momentum, which is the only power you have to counteract the friction on the runout. You referred to friction as aerodynamics, but a Pinewood Derby car's main friction comes in the form the moving parts. So what happens is that the cars build up momentum proportional to their weight as they roll down the hill and slough off this energy relative to their friction. So if two cars have similar coefficients of friction and one weighs 2 oz. and one 5 oz., the 5-oz. car will be running faster than the 2-oz. car across the line.
However, there is one more variable that needs to be addressed: the PEF, or
Parental Ego Factor. This has little to do with the actual speed of the
car, but it does have to do with the overall success of the race. The
Scouts in general seem to be plagued with PEF, and because of PEF generate
more misinformation about the world of physics (not to mention humanity)
than two men sitting in a radio station in Harvard Square.
Even though you didn't quite give the physically correct answer I have to commend you two for having misled this den mother. The misinformation you gave had all of the clues and none of the answers. I have had some experience with engineering types, as I am now getting my second bachelor's degree, in industrial design (imagine trying to get a job with a fine-arts degree). I have found that they often give the physically right answer without thinking if it is right or not. This is why my future profession exists and also why they hardly make any money (too many Scouts).
Ian Swope
B.A., Fine Arts
