Investigating the Strength of a Supermarkets Plastic Bag Essay Example for Free

Investigating the Strength of a Supermarkets Plastic Bag Essay buttI have been asked to investigate the strength of a supermarkets formative bag. I am going to demonstrate and analyse the plastic bag by investigating how applying a gradual increasing force effects the extension of the material.Apparatus* 30cm by 1cm disassemble of plastic bag,* Stand,* Clamp,* Boss,* Weights (N)- 100g* 2 wood blocks,* RulerMethod to begin with we toilet begin the experimentation my group and I forget have to set up the implement as shown on the diagram but with excluding the weights. We will set up the apparatus by in the altogether a 1 by 30cm strip of plastic from a plastic bag. We will proceed by placing the strip in between the two wooden blocks and then into the clamp. We will then begin the experiment by applying the first weight of 1 Newton. After applying the first weight we will then prise the length of the plastic strip leger the length and calculate the extension. We will c ontinue the experiment by adding another 1 Newton and recording the result and extension again. We will continue to keep adding 1 Newton and recording the results until the strip of plastic snaps or we have recorded a total of 10 results.We will redo the experiment twice again so that the results are more accurate and we piece of ass determine an average. To make trusted that we keep it a reasonably test we will make sure that we use the same length of plastic strip for each one time we carry out the experiment. When we change magnitude the force we will always increase by 1 Newton to keep it a fair test. We will be measuring the length and extension of the plastic strip in centimetres (cm). We are doing to this to measure it.Preliminary WorkBefore completing the plan we tested the experiment as explained in the method. We frame that as we increased the force in 1 Newton that the plastic strip actually snapped low an average of 3 Newtons which didnt give us enough results fo r the experiment. We tested this 3 times and found that this was accident for each time we carried out the experiment. To compensate for this we have decided to increase the force by sole(prenominal) half a Newton so that more results can be recorded. Whilst carrying out the experiment we did record a set of results as follows- sample 1Force(N)Length(cm)Extension(cm)0280128.40.4228.80.8329.31.3Experiment 2Force(N)Length(cm)Extension(cm)0280128.20.2228.60.63291Experiment 3Force(N)Length(cm)Extension(cm)0280128.50.5228.70.7328.90.9429.21.2From these preliminary results I can see that the plastic extends to no more than 1.3cm of its original length to begin with snapping. These results will help me with my prediction.PredictionI already eff that the plastic bag is make up of polymers. These are chemical bonds which make up the properties that form the plastic bag. The polymers in which plastic bags are made are more commonly known as polythene. Polyethylene is a straight chain poly mer. It consists of set up made up of only carbon and hydrogen. The bond that form the chain are covalent bonds and are held together by relatively weak electrostatic forces, because the bond carbon and hydrogen that form the polyethylene are covalent it means that they share electrons. The displayed formula for polyethylene isThe chains can go on and on,The longer the chains the stronger the plastic.Polyethylene is very cheap to produce. It is strong and easily moulded.There are forces playacting between the particles or molecules of the polyethylene which prevent the change in shape of the material, which when forces are applied can effect. Under the action of external forces the polymer bonds range and begin to roll out. At this point the plastic is actin as an elastic. As more force is applied will continue straightening until they reach a point of equal force, at this point the plastic is in a state of strain and can no longer straighten out. This is where the plastic begin s to act as a plastic. If more force is applied the bonds will snap and the plastic strip will also snap.After taking into account of the information I already know and the results from my preliminary work, I predict that as the force is applied to the plastic strip it will stretch as an elastic until the force becomes so great it reaches a point at which it can no longer stretch as the bonds have been straightened and weakened, at this point I believe that the plastic strip will snap.ResultsWhilst carrying out my experiment I recorded the following results,Experiment 1Force(N)Length(cm)Extension(cm)02801/2280128.20.21-1/228.20.2228.40.42-1/228.40.4328.60.63-1/228.70.7429.01Experiment 2Weight(N)Length(cm)Extension(cm)02801/2280128.20.21-1/228.30.3228.30.32-1/228.50.5328.60.73-1/228.80.9429.01.1Experiment 3Weight(N)Length(cm)Extension(cm)02801/228.10.1128.10.11-1/228.20.2228.30.32-1/228.50.5328.70.73-1/228.90.9429.11.1I am now going to calculate the average for the extensions of each experiment,Average resultsWeight(N)Average extension(cm)001/20.0310.11-1/20.220.32-1/20.430.63-1/20.841.0I am now going to plot a direct contrast graph for each set of results and my average results so that they can be easily viewed and analysed.I will use the line graphs to look for patterns and trends.I can also use the line graphs to determine whether I experienced any anomalous or irregular results.