Clamp & stand
Set up the clamp and stand so it holds the ruler and the elastic band.
Place the foam under the elastic band and put on the goggles.
Add masses to the elastic band and measure how much it stretches by as you add each mass.
Should you overextend the elastic band and it breaks the foam will catch the masses and any flying pieces of rubber will not go in your eyes.
Record your results in a table.
If you have time repeat your experiment a couple more times and calculate an average of the extensions.
Plot a graph of your results.
Try the experiment again with two and three elastic bands.
Try different configurations of the elastic bands, knotting them together lengthways, or placing them side by side.
How does this affect the shape of the graph and why?