This experiment aims to compare the elasticity of vulcanized rubber and unvulcanized rubber by measuring the change in length of rubber strips when weights are added and removed. The manipulated variable is the type of rubber (vulcanized or unvulcanized), the responding variable is the length of the rubber strip, and the fixed variable is the size and mass of the weights. The hypothesis is that vulcanized rubber will be more or less elastic than unvulcanized rubber. The procedures involve hanging rubber strips, measuring initial lengths, adding weights, measuring lengths, removing weights, and measuring final lengths.
2. (a) Aim of the experiment:
To compare the elasticity of vulcanized rubber with unvulcanized rubber.
(b) Manipulated variable: type of rubber//vulcanized rubber and unvulcanized rubber
Responding variable: length of the rubber strip
Fixed variable: size/length of the rubber strip, mass of weight
(c) Hypothesis:
Vulcanized rubber is more/less elastic than unvulcanized rubber
(d) Substance:
Vulcanized rubber strip , unvulcanized rubber strip
Apparatus:
Clip, weights, retort stand, ruler
(e) Procedures:
1. Hang the vulcanized and unvulcanized rubber strips on different retort stands.
2. Measure the initial lengths of both rubber strips.
3. Hang a weight to each of the rubber strips
4. Measure the length of the rubber strips.
5. Remove the weights.
6. Measure the lengths of the rubber strips.
(f) Tabulation of data:
Type of rubber Initial length/mm Length when the Length after the
weight is hung/mm weight is
removed/mm
Vulcanized rubber
Unvulcanized rubber
Or
Stretching phases Length of vulcanized rubber/cm Length of unvulcanized
rubber/cm
Before
During
After
