Physics Coursework - Making Sense of Data
Physics Coursework - Making Sense of Data The purpose of this investigation is to carry out two experiments, collecting a series of data. This will then be analysed and a conclusion will then be drawn, using my knowledge of physics. The purpose of the experiments conducted was to investigate the relationship between resistance and the dimensional properties of Nichrome wire. In both experiments the circuit was set out as illustrated below. The wire used had a single strand cross-sectional area of 33x10 cm. Experiment 1: Length & Resistance The first experiment explored the relationship between the length of wire and resistance. The different lengths of wire used ranged form 10cm to 100cm. A current was run through the circuit and the resistance across the wire was measured using an analogue meter. This data was then tabulated as shown below. Length (M) Volts (V) Amps (mA) Ohms R=V/I Resistance/Length .00 2.0 80 25.00 25.00 0.90 2.0 85 23.53 26.14 0.80 2.0 90 22.22 27.78 0.75 2.0 90 22.22 29.63 0.70 2.0 00 20.00 28.57 0.65 2.0 10 8.18 27.97 0.60 2.0 03 9.42 32.36 0.50 2.0 17 7.09 34.19 0.45 2.0 47 3.61 30.23 0.40 .9 55 2.26 30.65 0.30 .8 95 9.23 30.77 0.25 2.0 260 7.69 30.77 0.20 .7 250 6.80 34.00 0.10 .6 390 4.10 41.03 0.10 .0 390 2.56 25.64 It is very difficult to analyse, and
Physics Investigation Of Resistance
Physics Investigation Of Resistance Aim 1: To investigate how the electrical resistance of a wire changes in relationship to it's length. Resistance is when these electrons which flow towards the positive collide with other atoms, they transfer some of their kinetic energy. This transfer on collision is what causes resistance. Key factors: The factors in this experiment are ?The length of the wire ?The width of the wire ?The type of wire e.g. Nichrome ?The temperature of the wire ?The current passing through the wire The factor I will be changing is the length of the wire, I will keep all the other factors the Same. Prediction: I think that as the length of the wire increases so will the resistance of it. I also believe that the rate at which the resistance of the wire increases will be directly proportional to the length. I think this because electric current is the movement of electrons through a conductor. In this experiment a metal wire. So when resistance is high, conductivity is low. Metals conduct electricity well because the atoms in them do not hold on to their electrons very well. Free electrons are created, which carry a negative charge, 'jump' along the lines of atoms in a wire which are in a lattice structure. Resistance is when these electrons which flow towards the positive collide with other atoms, they transfer some of their kinetic energy. This
Aseptic Technique.
Aseptic Technique * Wipe the bench you are working on with disinfectant - this kills all the bacteria that may already be on the bench at the start of the experiment. The bench also needs to be wiped down at the end of the experiment. * Wipe tray that you will put all the equipment on with disinfectant - this is done to kill all the bacteria that may already be on the tray so that the sterilised equipment is not contaminated. * Sterilise all equipment - the equipment used is put in an autoclave which sterilises it so that bacteria on the equipment are killed and the equipment is ready to be used. * Light Bunsen Burner near equipment - this is done to create an up draught of air away from the bench to prevent contamination of cultures. * Wash your hands with antibacterial soap - this will get rid of any bacteria that may already be o your hands. Other safety precautions: * Wear safety goggles to protect your eyes * Wear a lab coat to protect your clothes from being contaminated with the cultures. * Cover all cuts Procedure . Collect all sterilised equipment and put on the tray that has already been disinfected. 2. Collect 10cm3 of the water sample in a sterile test tube and cover. 3. Prepare 4 serial dilutions of the original (10 , 10 , 10 , 10 ). Make sure a different pipette is used for each sample or else the samples will be contaminated. 4. Label the
nuclear power
Should nuclear power be used? Nuclear power stations use uranium -235 to create heat which is used to heat up water, the steam from the water is used to turn a turbine which powers a generator which creates electricity. Susie believes nuclear power is clean energy with very little effect on the environment. However Alan believes nuclear power is dangerous because it is unsafe and could damage the environment and be dangerous to humans. What Susie has said is true; nuclear power is clean energy because it does not release any pollutants or toxic gases. This is because the energy created in a nuclear power station is done by using the power of the atom to create heat energy. Although it doesn't release pollutants in the air it releases radiation. This however does not get release outside of the container which is lined with lead to stop any radiation escaping. This allows the area surrounding the nuclear power station to be safe. The area can be contaminated if the protective dome of the container becomes damaged or cracked. This would allow radiation from the station to escape. This is but a small issue as all nuclear power stations are fully maintained to prevent any harm to the environment. There is a vast amount of uranium so uranium -235 would be a fuel that could be used for years to come. This is a huge benefit because supplies of fossil fuels are quickly running out.
Nuclear Power
The benefits and drawbacks of Nuclear Power Nuclear Power is power that is generated by a controlled chain-reaction from nuclear fission in which a uranium-235 atom splits up into two daughter nuclei (Krypton-91 and Barium-143); the uranium also releases three neutrons when it splits. In nuclear reactors these neutrons are controlled by boron control rods so that only one neutron can get through to the next enriched uranium rod and initiate further nuclear fission, this process is called a chain reaction. In a nuclear power plant the vast amount of heat energy that is released from a chain reaction is carried to the heat exchanger, where the heat will be transferred into a water pipe, turning the water into steam (there are variations but the diagram above shows the major system). As in coal powered power stations this steam is then used to turn a turbine which in turn will turn a generator so an electrical current can be induced. Currently in the UK there are only 19 operational nuclear reactors generating 11852 megawatts of electricity, however the government wants to expand the UK's nuclear program so they can meet the targets set by the Kyoto Protocol of reducing the carbon emissions to 40% by 2050, nevertheless people are unsure about the environmental and social impacts of nuclear power. This report will explain the benefits and drawbacks of nuclear power using the
Nuclear Power
Nuclear Power Nuclear power plants create electricity using the energy released by splitting atoms to boil water and create steam which turns a steam turbine driving a generator. Since no fuel is burned, there are no gases or pollutants released into the air. The water used to create steam is isolated from radiation and any hot water to be discharged is cooled down in ponds or in tall cooling towers. Nuclear waste is the only byproduct of nuclear power and is packaged and stored rather than released into the environment. Unlike other fossil fuels, nuclear power plants release almost no emissions into the environment. Two different light-water reactor designs are currently in use, the Pressurised Water Reactor (PWR) and the Boiling Water Reactor (BWR). Diagram of a PWR In a PWR, the heat is removed from the reactor by water flowing in a closed pressurized loop. The heat is transferred to a second water loop through a heat exchanger. The second loop is kept at a lower pressure, allowing the water to boil and create steam, which is used to turn the turbine-generator and produce electricity. Afterward, the steam is condensed into water and returned to the heat exchanger. Diagram of a BWR In a BWR, water boils inside the reactor itself, and the steam goes directly to the turbine-generator to produce electricity. Here, too, the steam is condensed and reused. How a
Ohm's law.
Background Information, Introduction Ohm's law what is it about? "Ohm's Law states that the current through a metallic conductor at constant temperature is proportional to the potential difference. (p.d.). Thus p.d. over current is constant." GCSE Text Book. What is resistance? Resistance is defined as voltage over current. The unit of resistance is the ohm (?). So; Resistance = Background Information (Found in "Google.com") Electricity in wired circuits consists of the flow of electrons. Current is the word used to describe this flow, and is measured in amperes. Because positive and negative charge "dislike" being apart, current can only flow when a complete circuit exists: At least one closed loop for the electrons to run around. Current flows because of an electric potential-voltage-that exists in the circuit. An example of a source of voltage is a battery; here electrochemical reactions produce electric potential. Another example is a power generator powered by steam (a turbine) or by rushing water (hydroelectric generators). The former are examples of constant (DC) voltage sources (most flashlight batteries produce a constant 1.5 volts) and the latter AC sources, where the voltage varies in a pattern like that of a sinus curve. Circuits are comprised of the interconnection of circuit elements. Each element is distinguished by the relation it imposes
Ohm's Law Investigation
Safety -Follow basic lab rules -Don't overheat nicrome wire, use very low current to prevent wire breaking -Place all schoolbags under tables -Place stools under table Background Knowledge The flow of electricity along a wire is similar to the flow of water along a pipe. For more water to flow down the pipe, you have to push the water harder by turning the tap. This is the same in electric circuits. More current flows along a wire when the EMF pushing the electrons is greater. Ohm's law describes how the current and the voltage flowing a wire are related. Electrical resistance is a property of all materials. It measures how much the material inhibits the flow of electrons. High resistance allows a small amount of current to flow. This resistance is measured in ohms ( ). Nicrome wire opposes the flow of current more than copper, therefore nicrome has a higher resistance than copper. Non-metals insulate electricity, therefore they have a high resistance, whereas metals conduct electricity so they have a low resistance. The resistance of a wire increases with length, decreases if the cross section is increased, and also depends on the type of material. George ohm :Was German school teacher :Was born in 1787-died in 1854 :From 1852 until his death he was a professor of experimental physics. :The first scientist to discover the relationship that the current
Ohms Law.
Ohms Law Aims and hypotheses This investigation is designed to look into the resistance of different material in the form of wires and their conducting capability in different shapes. In order to do so, the materials are to be tested for their resistance in the shape of wires, and the hypotheses are such that different thickness and length of the wire and the material that makes up the wire itself will affect the electric conduction capability. Hence, the factors are: * The thickness of the wires: 1, 2 , 3and 4 mm in diameter * The length of the wires: 25, 50 , 75and 100 cm long * The material of the wires: copper, iron, constantan and nichrome * There will be 16 tests to be carried out The experiment will require both the readings of voltage and current in order to produce the value of resistance according to the formula: R = V/I ?? (Resistance is measured in Ohms) The power supply, however, is varied between 0-12V with 1V interval so that a series of results can be obtained with the single factor altered: a graph of V against I can be drawn and an average resistance can be produced in this case, rendering it a fairer test. Since each test does not take long, the tests can also be repeated to obtain a more accurate mean. DC supply is used so that the voltage and current are not fluctuating while a steady reading is needed to be obtained. To make it a fair test,
Electrolysis COursework
Electrolysis Coursework Aim: To investigate whether increasing the voltage through a copper sulphate solution increases the amount of copper extracted. Introduction: Electrolysis is the process in which an electric current flowing through a water solution of a chemical breaks that compound up into its component parts. I will be investigating how changing the voltage through an ionic copper sulphate solution, increases the amount of copper extracted on to the anode. I will do this by varying the voltage to calculate the effects of this factor on the original mass and solution mass after. From this I will calculate the difference, so it is easy to compare and evaluate. Apparatus: - Power Supply Unit (PSU) - Top Pan Balance - Wires - Electrodes - Anode - Electrode holder - 20cm³ CuSO4 solution - Small Beaker - Measuring Cylinder Prediction: I predict that the higher the voltage the higher the amount of copper on the cathode. In the same way, I also predict that the lower the voltage the lower the amount of copper on the cathode. Hypothesis: I base my prediction on my belief that when the voltage is low, the current is weak and therefore less can be separated. In the same way I believe that when the voltage is high, the current is strong so more of the solution can be separated. In electricity opposites attract. Therefore the metals ions, that are positively
