Resumen de "Having a Ball with Chemistry": More Things to Try.
A short outreach activity is described in which students test the rebound properties of superballs, racquetballs, "happy" balls and "sad balls" at many temperatures. After conducting the experiment, students use the test results to estimate the glass transition temperature of the elastic polymer that comprises each ball. The activity is used to segue into the classic demonstration of dipping a racquetball in liquid nitrogen and watching it shatter when thrown against a hard surface. In addition, students are encouraged to relate the results of the experiment to the importance of warming up muscles before exercise.
