Hypothesis through research Essay

Introduction This investigation aims to find the value of Young’s Modulus for a specific material, in this case nylon fishing line. Young’s Modulus (E) is a measure of a material’s stiffness, determined by the formula: The standard unit of measure for Young’s Modulus is the pascal (Pa). 1 pascal is the same measure as 1 Nm-2 (Nm being Newton Metre). A material always retains the same Young’s Modulus value regardless of how much it is stretched or strained, and this should be revealed in this investigation by gathering a definite value of the modulus for nylon. Hypothesis Through research that I conducted before starting the investigation, I have determined that the correct Young’s Modulus value of Nylon lies in the range 1-7GPa (the large range being due to different make-ups of Nylon with it being a compound). I should therefore be looking at achieving a final result within or very close to this range. Since stress is proportionate to strain in the Young’s Modulus formula, and the modulus value remains the same, I would expect the value of stress and strain to proportionally increase with each other. Experiment Plan In order to carry out this investigation into the value of Young’s Modulus of nylon, I will conduct an experiment to gather the values of stress and strain when increasing force is added to the material, and will take readings as weight increases until the breaking point of the nylon is reached. In order to calculate stress and strain, I will need to record each of the following variables throughout the experiment: Force applied to the material [F] (Newtons/N) Area of a cross-section of the material [A] (Metres-squared/m2). Original length of the material [Lo] (Metres/m) Amount of extension when the force is applied [L] (Metres/m) These variables will then allow the values of stress and strain to be calculated using the following formulas: This leads to a final Young’s Modulus calculation formula of: The set-up I will be using to carry out this experiment consists of the nylon fishing line suspended from a stand using a clamp, and another clamp to ensure there is no movement in the stand itself. I will create a suitable loop at the bottom of the hanging material so that weights can be added but will need to ensure this loop does not weaken any area of the material and cause a drop in the breaking point value, as this would compromise the reliability of my experiment and result in premature breakage of the length of nylon. At each stage of the experiment I will take readings of length using a standard 1m ruler, and will measure the area of a cross section by gathering the diameter value using a micrometer, halving this value to gather radius and then use the formula. Before any weights are added, I will need to take a control measurement of the length and area of the nylon before any stress or strain is applied. Once this is done I will proceed to apply weight in intervals of 100g (0. 981 N) and record the values of each variable stated at bottom of the previous page after each 100g weight is added, with the exception of original length which is a constant value and only needs to be recorded at the beginning of the experiment. I will continue to add weights until the material reaches its elastic limit and snaps, at which point I will record the force applied to break the object. In order to achieve an adequate number of results from each experiment to make a fair analysis and conclusion to the investigation, I will need to take a minimum of eight readings (i. e the nylon should withstand at least 800g/7. 849N). If this fails in the actual experiment then I will need to re-evaluate my plan and decide on a new method of conducting the experiment to meet this criteria. To increase reliability, accuracy and to eliminate possible anomalous results, I will aim to repeat the entire experiment three times to gather average readings.