Energy in a falling mass on a Spring Essay Example for Free

Energy in a falling mass on a Spring Essay The aim of the experiment is to design a temperature measuring device, using a Wheatstone Bridge, with two fixed resistors of 47 ohms and then to implement it. The idea is to end up with a comprehensive set of results which allows us to work out an average, and then plot graphs to show the different variables. Preliminary work: Before I started the actual experiment, I did some preliminary work to find out the best set up for the apparatus I was using. It was also to test out the different apparatus that was available to me and to build a circuit which was set up to do the task which was required. Preliminary Diagram: The apparatus was set up as shown below: Preliminary Method: The apparatus was set up as shows above, and then filled the beaker to half full with iced water. I then put the thermometer in the water and added more ice until the water temperature reached zero. Then I put the thermistor in the water and waited until the ammeter reading was constant, and then adjusted the resistance using the variable resistor until the ammeter read nought. Then I recorded the resistance at that point. I did this once for each temperature. I decided that a reading every ten degrees was the optimum range, as this would give me a good set of results, without having too much information which I would not need to use. Diagram of experiment: Method of experiment: I used the same basic method as the preliminary experiment, with the following alterations: I did three repeats to find an accurate average result, which will enable me to plot graphs showing different factors. I used the results from the preliminary experiment to predict the resistance in the actual experiment, and I set the variable resistor to that resistance, then adjusting it slightly until the ammeter reads nought. I heated the water with a Bunsen Burner as this is quicker than leaving it to warm normally. I was able to do this as I knew what I was doing, due to the fact that I had done the experiment before in the preliminary. It also gave me time to do more repeats. Safety: Safety is an important factor to consider while doing this, and any other experiment. As we are using Bunsen Burners, heat proof mats will be used, as will safety goggles. The electrical apparatus will be kept well away from the flame. Gloves much be worn when handling the beaker when it is hot to avoid burns. Also books will not be kept on the benches where apparatus is set up, and loose clothing/hair will be tied back. A sensible approach will be taken and behaviour will be in line with the lab rules laid down by the college. Background Physics/Own knowledge: Wheatstone Bridge: This circuit enables resistance to be measured more accurately than by the digital ammeter. It does not rely on the accuracy of instruments, but resistors of a fixed known resistance have to be used. The four resisters used are called P, Q, R, S. The ratio between these resisters is: P R Q S The resistance to be found is P. Here is a diagram of a Wheatstone bridge: Thermistors: Thermistors are made out of semi-conducing metals because the resistance of these decreases with an increase in temperature. A thermistor is a resistor, and its resistance changes when its temperature changes. When the liquid the thermistor is in increases in temperature, the atoms in the head of the resistor get more energy and as a result they vibrate more, increasing the number of electrons which lowers the resistance. Microsoft Excel: I will use Microsoft Excel to present my data in table and graphical form. I shall also use it to work out the following: Sensitivity, average resistance, resolution and reaction time. Once I have this data, I shall present it graphically using excel, and I shall draw the following graphs using the data I have worked out: Temperature vs. Sensitivity (1). Preliminary resistance vs. temperature (2) Average resistance vs. temperature (3) Analysis: From my results I can see that as temperature increases the average resistance decreases. This can be clearly seen on the graph, which has an exponential shape. I have no anomalies in my average resistance, as the line of best-fit on the graph passes through all the error bars. I think that overall the experiment was conducted and executed well with no apparent disastrous inconveniences. There was however, a very small problem, which I encountered during the course of the experiment. The original thermistor that I began to use for my preliminary experiment decided to cease to function. This resulted in a loss of time, as I had to repeat my preliminary experiment so that any results conducted were not fair. Conclusion: The displacement increases and the velocity increases then decreases. The same happens with time and height. Displacement increases and the total energy decreases minimally as the energy is transferred to heat while the elastic potential energy increases and the gravitational potential energy decreases. Kinetic energy rises and falls as the spring is dropped and gathers speed before the spring takes the tension and slows it down. I conclude that energy cannot be lost, only transferred from one form to another, and this experiment proves it.   Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section. Download this essay Print Save Not the one?