|MadSci Network: Physics|
Ashley, As an experiment I attempted to duplicate Hooke’s law in a Physics class with rubber bands. We got a huge surprise. We hung rubber bands of various sizes over a support, attached a plastic pail, and began to fill it with sand. At first the band appeared to follow the expected pattern. With increased sand and the resulting force the band elongated. But; as we approached the elastic limit, it not only stopped lengthening it sometimes actually contracted! It was almost as if the band tried to resist breaking. Of course it can not. So what was happening? We don’t really know. After trying a number of different bands we found that brand, age, thickness, length, method of attachment, and rate of increasing force all influenced the elastic limit. But no matter what we did they all underwent the “resist breaking” phenomenon. I recommend you do this outdoors with water on a warm day. That way you can estimate the mass by keeping track of the volume since one Liter is about one Kilogram which is around 9.8 Newton. Maybe you can discover some kind of relationship…we never did find a reliable predictor of performance. By the way…get ready to get wet! Have Fun, Ed Stammel firstname.lastname@example.org
Try the links in the MadSci Library for more information on Physics.