Inquiry in Action 3
How much can you stretch a snake? or Determine the Snakes Structural Strength?
Materials Jelly snakes of various colours, plastic rule, length of rubber band 10 cm long.
a) Hold one end of the rubber band so the end rests on the zero mark and check its exact length. Now stretch the band to three times its length and hold it there for 10 seconds. Gently release it and note whether it returns to exactly its original length. Materials that always return to their original size after distortion are said to be elastic. Is rubber perfectly elastic? Glass is!
b) Now repeat the experiment with a red jelly snake. What can you say about its elasticity?
c) Try the other colours. Is there a difference in the elasticity of the different colours?
Independent variable (we are changing)
Dependent variable (we are measuring)
Controlled variables (all other variables need to be controlled)