The aim of my investigation is to find out if the motion of an elastic band changes, by the rate of its extension. So in other words if an elastic band is extended to 20cm, will it fire a greater distance, than a band which is extended to 10cm, and if so why? Research You can change the shape of a material by applying enough force. When you stop applying the force, some materials retain their new shapes; these are plastic materials. Other materials return to their old shape when you stop applying the force; these are elastic materials.
Elasticity is the ability to return to their original shape after being stretched, for example: an elastic or rubber band. When you pull an elastic material, it stretches and increases in length. At first, when you double the pull, you double the increase in length. However, as the pull increases, you reach a point where the material no longer returns to its original shape. This pull is the elastic limit of the material. Energy transfer Energy is the capacity to do work. There are ten types of energy transfer each of which are explained below. Most types of energy are ultimately derived from the sun, or from radioactivity.
All types of energy are measured in joules (J). Electrical energy = whenever a current flows. Light energy = From the sun, bulbs etc. Sound energy = Energy that has sound or noise coming from it, for example: loudspeakers. Kinetic energy = Energy of motion. Includes heat, sound and light (motion of molecules) Thermal energy = flows from hot objects to colder ones. Gravitational potential energy = Potential energy due to elevated position. Possessed by anything that can fall.
Elastic potential energy = Potential energy due to tension-either stretch, for example: rubber bands etc.or compression, for example: springs etc. Chemical energy = Possessed by foods, fuels, and batteries. The principle of the Conservation of Energy is: Hypothesis I predict that as the length of the extension increases, so will the distance travelled by the elastic band. This is because the further the extension, the greater the force there is within the band that is able to push against the resistance of the air easily. While the band is being extended, it holds a lot of stored energy within it, otherwise known as potential energy.
As the band is released this potential energy is transferred into motion energy, known as kinetic energy, which is the transferred gravitation potential energy, while the band is moving through the air and against the gravitation forces acting upon it. So therefore all kinetic energy produced will convert in to gravitational potential energy as the band is released. Also as the graph states the bigger the extension, the more force is held within the band, therefore the more potential energy it will hold that can be converted to a larger amount of kinetic energy and a larger result of gravitational potential energy.
Variables In order for my results to be valid, the experiment must be a fair one. I will keep the height of the meter stick off the floor the same. I will use the same elastic band for each recording I might not have enough time in one lesson to collect all the results needed. Therefore, I will leave the meter stick taped to the chair, and place it in a secure cupboard where it cannot be tampered with. Hence the meter stick is in the exact same position as previously when I come to use it again the next day in my lesson. Equipment/Apparatus:
Below is a list of apparatus I will use during my preliminary series of experiments. If everything goes accurately and correctly then I will use this list of apparatus for my real experiment. Elastic band Meter stick Measuring tape Laboratory chair Preliminary Experiment In order to obtain the best results possible, we carried out some preliminary work in order to identify appropriate ranges and values, to be used in the final experiment. The 1st stage of my preliminary work was to find a suitable type of elastic band to use within the experiment.
Ideally we needed a band that would be able to be extended easily, and that when would land, would not move any further forward, so that a reading can be obtained easily and to the best accuracy. I collected a number of different sizes and width elastic bands and catapulted them off the end of a meter rule along a corridor. I chose from a choice of a: Short, thin elastic band A short thick, elastic band A long thin elastic band Along thick elastic band. We immediately ruled out using the short thin elastic band, as it was:
(a) Too hard to extend, which would mean it would be difficult to extend to various lengths. Therefore, I wouldn’t be able to get a varied range of readings. (b) Because when the elastic band was released of the end of the meter rule, it travelled much too quick and high, and not straight enough, in that I couldn’t determine an accurate reading. The elastic contained too much tension within it while it’s being extended. We had slightly the same problem with the short thick elastic band. However, we found that the best elastic band was the long, thick elastic band, because it’s heavier.