paper cones investigation

Investigation Report Aim Theory When an object is dropped in air, it accelerates. If it is allowed to drop far enough then it can reach its terminal velocity. This is the maximum velocity of the object during its fall and occurs when the upward force of air resistance acting on the object equals the weight of the object. So at terminal velocity... (P.31, Complete Physics, 1999, Pople, Oxford University Press, ISBN 0-19-914734-5) (P.33, Physics 1, 2000, Cambridge University Press, ISBN 0-521-78718-1) Looking for a formula for air resistance... F = force of air resistance ? = density of air = 1.2kgm-3 c = coefficient of drag for the object / dimensionless A = cross-sectional area of object hitting the air / m2 v = velocity of the object / ms-1 (http://damonrinard.com/aero/formulas.htm) Looking for a formula for the weight of an object... W = m.g W = weight / N m = mass / kg g = acceleration due to gravity, 9.81Nkg-1 (P.55, Physics, 1991, Robert Hutchings, Nelson, ISBN 0-17-438510-2) So putting these formulae together... From the Physics AS course, v = velocity x = displacement t = time so References to the specification Forces and Motion 2821 Forces, Fields and Energy 2824 Aim of your investigation The aim of this work is to investigate the relationship between the time taken for a paper cone to fall and the mass of the cone. Variables

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Internal Resistance of a cell

Topic: Internal Resistance of a cell Aim: To measure the internal resistance and emf (the potential differences across a voltage Source when no current is flowing) and to observe the combination of cells Hypothesis: The emf of the old cell is less than the emf of the new cell but the internal resistance of the old cell is much greater than the new cell. Introduction: Resistance in electricity, property of an electric circuit or part of a circuit that transforms electric energy into heat energy in opposing electric current. Resistance involves collisions of the current-carrying charged particles with fixed particles that make up the structure of the conductors. Resistance is often considered as localized in such devices as lamps, heaters, and resistors, in which it predominates, although it is characteristic of every part of a circuit, including connecting wires and electric transmission lines. (Britannica.2006) The dissipation of electric energy in the form of heat, even though small, affects the amount of electromotive force, or driving voltage, required to produce a given current through the circuit. In fact, the electromotive force V (measured in volts) across a circuit divided by the current I (amperes) through that circuit defines quantitatively the amount of electrical resistance R. Precisely, R = V/I. Thus, if a 12-volt battery steadily drives a 2-ampere

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The Compound Pendulum

The Compound Pendulum Task: * To confirm that a metre rule behaves as a compound pendulum when oscillating; * To determine the acceleration due to gravity using a compound pendulum. Planning: Sources used in research of the above tasks are: . A Text-Book of Practical Physics - William Watson; page 129 2. Laboratory Physics - JH Avery & AWK Ingram; page 69 3. Intermediate Physics - CJ Smith; page 50 4. The Text-Book of General Physics - GR Noakes; page 394 5. Intermediate Mechanics - D Humphrey; page 60 6. Introduction to Physics for Scientists and Engineers (Second Edition) - Frederick J. Bueche; page 222 7. http://www.physics.mun.ca/~cdeacon/labs/simonfraser.pdf 8. http://hyperphysics.phy-astr.gsu.edu/hbase/pend.html 9. http://en.wikipedia.org/wiki/Acceleration_due_to_gravity 0. http://geophysics.ou.edu/solid_earth/notes/potential/igf.htm 1. http://www.gorissen.info/Pierre/maps/googleMapLocationv4.php 2. http://en.wikipedia.org/wiki/Reaction_time Where direct quotation is made from a source, the source number is shown in superscript after the preceding italicised quote, e.g. 'quote' 4 . The compound pendulum is defined as: 'a rigid body of any shape and internal structure which is free to turn about a fixed horizontal axis, the only external forces being those due to gravity and the reaction of the axis on the body' 3. In this investigation a wooden

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Measurement of the resistivity of Nichrome

Measurement of the Resistivity of Nichrome (NiCr) Introduction In this coursework, I am going to measure the resistivity of Nichrome. Nichrome is a non-magnetic alloy of nickel and chromium. It is a good conductor of electricity and heat, and has a high melting point. Due to its relatively high resistivity and resistance to oxidation at high temperatures, the wire made of Nichrome is widely used in heating elements, such as in hair dryers, electric ovens and toasters. What does Resistivity mean? Resistivity (also known as electrical resistance) is a measure of how strongly a material opposes the flow of electric current. It is normally static and could be varied by changing the temperature. In general, resistivity of metals increases with temperature, while the resistivity of semiconductors decreases with increasing temperature. High values of resistivity imply that the material making up the wire is very resistant to the flow of electricity. Low values of resistivity imply that the material making up the wire transmits electrical current very easily. The unit of resistivity is the ohm meter (? m). The resistivity ? (rho) of a material is given by > ? is the static resistivity (measured in ohm metres, ?·m); > R is the electrical resistance of a uniform specimen of the material (measured in ohms, ?); > L is the length of the piece of material (measured in

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Investigating the forces acting on a trolley on a ramp

Physics coursework Investigating the forces acting on a trolley on a ramp Contents Page 3 -> Method Page 4 -> Theory Page 7 -> Results Page 9 -> Error Page 18 -> Appendixes Method The aim of the investigation was to investigate the forces acting on a trolley as it rolled down a ramp, and also to investigate the factors which may contribute to the results. To do this, a trolley and a ramp set at a variety of angles of incline were used, and then, using a light gate, the speed at which the trolley was moving when it passed through the light gate was calculated. The variables were the starting distance of the trolley in relation to the light gate and the angle of the ramp. Firstly, the equipment was set up as in fig. 1. The trolley was then run down the ramp with a piece of card attached to the side. This card was of a known length and could hence be used to calculate the velocity at which the trolley was moving. While the light gate did actually calculate the velocity, it only gave the answer to 2 decimal places, whereas it gave the time to 2 decimal places. Furthermore, the light gate calculated the velocity with the assumption that the card was exactly 100mm, whereas when the card was actually measured, this was a value closer to 102mm (±0.5mm). Next, after the trolley had passed through the light gate, the information from that 'run' appeared

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Sensing project

Sensing project Project brief A new greenhouse is being developed for gardeners who are concerned about overheating plants in their current greenhouses. The new greenhouse has been built with opening windows but occasionally the windows of the greenhouse slips fully open and allow all of the trapped heat in the greenhouse to escape quickly. This is a major concern for serious gardeners. The test is to develop a sensing circuit that will sense whether the windows are fully open, so a gardener can be alerted of the problem. Introduction To begin we must know what a sensor is. A sensor is an electrical component, which produces a signal in response to alteration in its surroundings, this maybe an alteration in a physical variable or by movement of objects. The sensor planned for the sensing circuit ensuring the windows are not fully open is a rotary potentiometer. A rotary potentiometer is a component, which has three terminals. When the angle of rotation is changed on the component's arm then the potential difference (often called voltage) is also changed. Once the voltage reaches a specific point a separate circuit could activate an alarm showing that the window has slipped and is fully opened. The potential difference is the difference between potential energy between two separate points. Alternatively a different sensing circuit could be used. A circuit with

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The advantages and limitations of electron microscopy.

The advantages and limitations of electron microscopy There are two main branches of microscopy that are pertinent to cell biology. These branches arise from the two types of microscope; the light microscope and the electron microscope. The basic principles of light microscopy have been known since circa 17th century, however improvements in lens manufacture in circa 19th century allowed the use of microscopy to be much more practically available and useful. This is increased ability inspired rapid research into both the design of microscopes and the preparation of specimens. However, the light microscope can only magnify objects bigger than 0.2 micrometres; due to its limited resolving powers. This is because it utilises a beam of light. Relatively, light has a long wavelength, this means that when there are two small points close together there is too much refraction and wave front overlap, the eye then only sees one point. This can also be considered in terms of objects "crossing the path" of the wavelength. The smallest wavelength of visible light is 400nm, the diameter of mitochondria is 1000nm, and therefore mitochondria cross the path of the light wave. However ribosomes have a diameter of 22nm, and do not cross the path of the light wave and are therefore not seen by the light microscope. As biologists came to realise these limitations they understood that the

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investigating the relationship between the diameter and the current in a wire at its melting point

Investigation Report Aim Theory Electrical resistance is a measure of the degree to which an object opposes the passage of an electric current. The SI unit of electrical resistance is the ohm. Its reciprocal quantity is electrical conductance measured in siemens. Resistance is the property of any object or substance of resisting or opposing the flow of an electrical current. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied to the circuit. Some formulae for resistance are where R is the resistance of the object / ? V is the potential difference across the object / V I is the current passing through the object / A (Ref. http://en.wikipedia.org/wiki/Electrical_resistance) where R is the resistance/ ? ? is the resistivity / ?m l is the length of the wire / m A is the cross section area of the wire / m A = ?() = ? where A is area / m d is the diameter / m Putting the formulae together, so (Ref. http://physics.bu.edu/~duffy/PY106/Resistance.html) Aim of investigation The aim of this work is to investigate the relationship between the resistance and the diameter of the wire. Variables Variable Independent / Controlled / Dependent Resistance D Resistivity C Length of wire C Diameter I Prediction Since the theory suggests that So So the resistance should be

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Are mobile phones a health risk?

Abstract In this report I aim to determine whether or not mobile phones pose a risk to our health. I will explain how mobile phone electromagnetic radiation can be perceived as dangerous, with reference to the EM spectrum. I will cite scientific sources of evidence which support both sides of the dispute, and will come to a reasoned conclusion as to how likely it is that mobile phones are a health risk. I will also evaluate the credibility of the sources used to support my conclusions, and list all the sources used throughout in a detailed bibliography. Introduction Mobile phones are becoming increasingly popular in today's world; with around 80 million handsets in Britain, there are now more mobiles than people [1]. They've become an essential part of our existence, in business, in our daily lives and in keeping in touch with our loved ones - however, there is growing concern that this technology is causing serious health problems throughout the population, such as lasting brain damage and cancer. The Media consistently tends to portray mobile phones negatively, fuelling the public's fears and misgivings: this study aims to determine from the scientific evidence whether or not mobile phones present a risk to our health. Main Points How might Mobile Phones be Hazardous to our Health? After studying numerous publications, I have found that if there are concerns about how

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Electrical Hazards.

Electrical Hazards, risks of injury or death arising from exposure to electricity. Electricity is essential to daily life, providing heat and light and powering appliances in homes and factories. It must, however, be treated with great care, because the consequences of an electrical fault can be serious and sometimes fatal. Generally voltages greater than 50 volts can present a serious hazard and currents of more than about 50 milliamps flowing through the human body can lead to death by electrocution. A shock occurs when a "live" part of some device is touched, so that current passes through the body. Its severity depends on many factors, including the body's conductivity (the ease with which electricity passes through it). The conductivity is usually small, but can be increased if the body or clothing is wet. The risk of injury also increases according to the size of the voltage or current, or the duration of contact. There is a risk of electrocution (death by electric shock) if current passes across the heart. For example, if one foot is touching wet ground, the risk is greater if the arm on the opposite side touches a high-voltage source than it would be if the arm on the same side did so. Current passing into the body generates heat, which burns the tissue. Electricity can also present less direct risks. Burns are caused when hot surfaces on electrical appliances are

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