Physics CAU - Elasticity- Describe the energy transformations involving elastic objects.
- Investigate elasticity of of rubber -State Hooke's Law The context of the CAU: A suitable elastic cord for a bungee jump What factors are important to consider when choosing the bungee cord for a bungee jump? - Force applied - Thickness of cord - The elasticity - The material - Elastic limit - Original length/heigh - Temperature THINK ABOUT: How might the results of an investigation be useful when choosing a bungee cord suitable for a bungee jump? In your method you should state: What exactly you will do? Measurements taken and how Is it a fair test? How will you control/ monitor the values of the controlled variable? THINK ABOUT: What made you choose your hyposthesis? How useful did you find the references? What is good/bad about them? The resolution of the half-meter ruler is 1mm. Why is this a suitable resolution? |
If you apply a force to a spring, kinetic energy that caused it to move gets transferred into elastic energy. The springs would stretch and change shape. When you release it, the shape should go back to normal.
The same applies to elastic bands with masses on it. Hooke's Law states that when an elastic object is stretched by a force, the extension measured will be directly proportional to the force applied. Hooke's law: F= K x E F= force applied K = spring constant E = extension As the mass increases, the greater the extension thus satisfying Hooke's Law. Also, every elastic object has a limit of proportionality. Beyond this force limit, materials can become permanently stretched. Your hypothesis must investigate a factor that may affect the extension of a rubber band. Possible hypothesis: 1) The extension of a rubber band depends on the force applied to the rubber band 2) The extension of a rubber band depends on the width of the rubber band used 3) The extension of a rubber band depends on the temperature of the rubber band. We're using the first one because it is easier to investigate and understand. We now need to state our independent, dependant and controlled variables. Independent- The force applied Dependant - Extension Controlled: Orignial width of rubber, band, original length of rubber band, original thickness of rubber band and original material of rubber band. |