Other
Engineers Edge: Strenght of Materials
This site has information about the strength of materials. Covers various types of stress and yeilding. Formulas included.
University of Cambridge
University of Cambridge: Maths and Sports: Making a Racket: The Science of Tennis
As London is heading for the 2012 Olympics, it's not just athletes who are gearing up for action. Engineers, too, are working hard to produce the cutting-edge sporting equipment that guarantees record performances. If you're a tennis...