Joules law Essay

Variables and agelesss The mavin variable in this experiment allow be the charge situated upon the conducting outfit, this is the obvious variable because as seen in the formula. By rearranging the formula to e = F L A E We washstand see that in that respect are 3 main(prenominal) factors which will effect the verbotencome of the experiment. The E symbolizes Youngs modulus, which will be effected by varys exactly is non itself a single factor as it is a touchstone of the factors. In order for the experiment to be a success, it has to be a fair test.Thus of course meaning that factors that need to be kept constant must be set and kept that room. In this scenario I will be isolating drive as my variable. Force is at once related to the payload on the wire only multiplied by the gravitational pull (approx. 9. 81) as the load is measured in Kg as it is a mass. From the equation we locoweed see that a change in Force will indeed affect the character reference of the wire, at this stage it is apparent to say that Theoretically the larger the force the greater the extension according to the equation in a higher place, as it is the nurse that is world divided. succeeding(a) this it is as well as imperative that both the Cross sectional area of the wire is indeed accurately measured, as well as remaining constant through with(predicate) out the experiment, as a change in this value would indeed effect the value for Tensile stress, and in turn the extension. The duration of the wire must also remain consistent through out the experiment. This is because each unit of wire will stretch or dilute by a proportional amount to the load being utilise to it. Thus changing the length of will increase or diminish the amount of units of wire that can be stretched, causing different readings to be measured.The wire will indeed elongate and extend no affair what the length, but for these experimental purposes it is best to be long as explained above to stand a greater chance of measuring it properly. The important subject is to set the length of wire you wish to work with and do not change it.B) Implementing Results, observations and description. Cross sectional diameter of wire Measurement account and degrees of rotation 1/mm 2/mm 3/mm Average 0 Calculation of Average wire diameter= (0. 195 + 0. 185 + 0. 1925) / 3 = 0. 1908mm Thus the average cross sectional area of the wire is Force = mass 9. 81 ms.Table of readings Final length, attempt Mass/g Mass/Kg Force/N Orig. L/M 1/M 2/M 3/M Mean accessory/ Unfortunately actus reuss can easily occur in this experiment, the first look of minimizing the percentage error in the experiment is to identify the sources that could cause such a problem these being. When measuring the extension there are 3 main sources of uncertainty.Meter rul Parallax error Zero error I syllabus to besmirch these by* Careful choice of meter rule, as humanity are bent and warped Fixing a head and nitty-g ritty position against something so that the parallax error is minimized as I will be looking at the ruler from exactly the same angle. register results from 0. 0 M If there is a zero error, take it a elbow room(predicate) from the results. When measuring the free lean of the mass the following sources could effect the results Zero error on the scales Not allowing for the weight of the cradleSimply using the weight that is imprinted on the mass instead of weighting it. I will minimize these sources by selecting my masses carefully and weighing each one by the piece to find its exact weight, as well as double checking a pair of scales against each other by putting the same weight on both scales to see if there is a zero error. The final measurement source of error is the measurement of the diameter of the wire. This is typically a source of inaccuracy because the wire does vary in cross sectional area, because of the way it was made.This can be accommodated for by measuring the wire extremely accurately with the micrometer, and measuring the wire in three different areas of the length and taking two readings at each of the three points along the wire, twisting it 90 degrees at each point to allow for ovals etc. The average can then be taken and used in the calculations to give a better representation of the wire being used Diagram of holy man and misshapen wire. Observations for experiment conducted on the 14th of December 2002 At well-nigh 0930 the equipment was set up and the working area was in suitable configuration to go ahead with the experiment as planned.I had two main concerns whilst conducting the experiments, these were of measuring natures, the first of these being that, when measuring the wire with the micrometer it proven initially extremely hard to turn the wire 90 degrees, I quickly remedied this by sticking a label on the wire so that it was clear what angle the wire had to be turned. The second was that of concerning minimisation of t he parallax error, this proved to be quite challenging, so we decided to look at the ruler twice each a couple of seconds apart and in what i8 thought was the same position to see if it was a fair test.This way through up different results so we deemed it necessary to have soul stand over the wire and not move until the experiment was sunk to minimize this risk. Another observation I made was that I didnt think we were measuring the extension accurately enough I tangle that measuring it to 1mm was far to inaccurate as the extension as will be seen by the graphs was minimal, I will mention this point hard in the Evaluating. The equipment was packed away and the experiment was completed within the hour. I observed a changing in mass or load on the wire and no change in any of the identified variables.C Analyzing Evidence and Drawing Conclusions. Force/N Area/M Sress/Nm (Pa) Length/M Extension/M Strain Youngs modulus 1 The stress was simple to calculate as it simply meant dividing the force by the area, as so The strain is a simple ratio it involves dividing theextension by the length Thus the youngs modulus can be imbed for every plotted point separately on the graph this is make by dividing the stress by the strain.As I predicted earlier the substantive obeys hookes law and froms a straight line through the origin until the live limit is reached. As well as we can calculate the extension from the gradient of the graph because its equal to L / EA. When a material obeys Hookes law, then its force, extension graph is a straight line through the origin (see graph). This is only the case up to the proportional limit. The graph being a graph of force against extension, the area is the energy stored in the wire. As the equation of the graph is F=kx, the equation of the area is .From the graph we can say that as the load increases on the wire the extension also increases proportionally, up to a certain point known as the tractile limit, this is because it is o beying kooks law as described above, and for this material whilst under low load the strain is proportional to the stress.. Show dawdler only The above preview is unformatted text This student written piece of work is one of umteen that can be found in our GCSE Electricity and Magnetism section.