A study on the stretching behavior of rubber bands
(1) Delhi Public School, Bhopal, India, (2) Composite Regional Centre for Persons with Disabilities, Bhopal, India
Rubber bands are simple and familiar household items whose properties are worth researching to determine their utility and value. They are used ubiquitously, as toys, binders for objects and as equipment in the fitness industry, which necessitates study of their properties and manufacturing and labelling them based on standard extensibility and strength, specific to utility. Our study aimed to investigate the applicability of Hooke’s law to rubber bands. We hypothesized that rubber bands are ideal elastic materials, exhibiting stretch in direct proportion to loads and that bands of any length respond equally to pulling forces. We exposed a few rubber bands to a step-wise longitudinal loading process, and the stretch response after each step of the load was measured. While the initial loading steps removed only the slack of bands, a marked stretch behavior was observed soon. A linear relationship between stretch and applied force, noted in a few intermediate steps, was lost eventually. When we compared the bands of different lengths, it was obvious that the shorter bands stretched less than the longer ones for similar loading. Finally, we rejected the hypothesis since the findings supported that rubber bands do not follow Hooke's law and that their initial lengths affect the stretch response for loading. This study can be used in further research of the properties and molecular structure of rubber bands and to compare them with some visco-elastic structures.