Stretching an elastic band

This video demonstrates the stretching of an ordinary elastic band using 100g masses. The masses are first loaded on to the band, and then removed one at a time. A close up on the masses allows measurements to be taken from which the extension can be calculated and a graph plotted. Close observation also reveals that the band continues to extend after the masses have been applied, and remains slightly stretched after their removal, resulting in a hysteresis curve.

The main points of the video are:

• • Non linear (plastic) behaviour (does not obey Hooke's law)

  • Creep

  • Hysteresis curve.