EvaluationThis article of "What We Know About Police Use of Force" is helping in putting police use of force into context in order to understand the potential magnitude of use of force problems
"What We Know About Police Use of Force" by: Kenneth Adams Thesis Police use of force is one of the most sensitive subjects in American policing history. This subject has been depicted in many different ways. It's a subject of what is too much and when should it be used. Finding the thesis of this article was quite a chore for me. I feel that Adams thesis is that it is important to put police use of force in context in order to understand the potential magnitude of use of force problems. Putting this issue into context will help reduce some future conflicts, issues and help gain a greater degree of control over use of force used by the police. He also discusses the importance of society striving to minimize police use of force as much as possible. Method This article consists of results from of many different references and sources. The references and sources used in this article are very knowledgeable and are helpful in coming to a conclusion about police use of force. * In helping to bring understanding about the topic, Joel H. Garner and Christopher D. Maxwell are referenced by using their work " Measuring the amount of force used by and against it police in six jurisdictions" which is found in Use of Force by Police, National Institute of Justice-Research Report. (P. 133-134) * Also helping this article was information by Geoffrey P. Alpert and Roger G. Dunham.
To investigate how the depth of sand in a cylindrical vessel affects the amount of tilt to which the vessel can tilt to whilst remaining stable.
James Bolton 9HS Physics AT1 Aim: To investigate how the depth of sand in a cylindrical vessel affects the amount of tilt to which the vessel can tilt to whilst remaining stable. Prediction: As the level of sand within the vessel rises so will the amount to which it can be tilted remaining stable, this is until the sand level is over halfway through the vessel vertically, where it will begin to become less stable again. Hypothesis: The centre of gravity, or centre of mass is a point through which the whole weight of an object seems to act. There are several factors that can affect the positioning of the centre of gravity. In this case, the factor investigated will be the depth of x (sand). Sand has a mass, and so when added to the cylindrical vessel will alter the total mass of the vessel. This change in mass will thus change the positioning of the centre of gravity as more matter is now in the vessel : As more sand is added, the position has altered. An object is unstable when it can no longer fall back on its base when tilted so far. Instability is caused when the centre of gravity of an object is no longer over the pivot through which the object is being tilted: The object on the right is unstable as the centre of gravity has passed beyond the pivot, is the object is released it will not fall back onto its base. So by changing the position of the centre of
Solenoid Investigation
Oxford Cambridge and RSA Examinations Advanced Subsidiary GCE PHYSICS A (2823/03/PLAN) Practical Test (Part A - Planning Exercise) Research/Theory "The moment of a (turning) force about a given pivot is defined as follows. Moment of a force = force x perpendicular distance from the pivot to the line of action of the force. The unit of moment is the Newton metre (Nm)."1 Also, "The principle of moments states that for any body in equilibrium, the sum of the clockwise moments about any pivot must equal the sum of the anticlockwise moments about that pivot."1 (Fig. 1) "Inside a solenoid, the magnetic field is uniform and its strength can be increased by increasing the current."2 The principle of moments is used to find attractive force between the magnet and the solenoid. The unknown force is the one produced with the bar magnet and solenoid. By using the equation of equilibrium previously given, the unknown force can be calculated provided that the system is in equilibrium: F1 x d1 = F2 x d2 F1 = (F2 x d2) / d1 F1 = Unknown force between the magnet and solenoid. (Newton / N) F2 = Force produced by mass. (Newton / N) d1 = Perpendicular distance between pivot and magnet. (metres / m) d2 = Perpendicular distance between pivot and mass. (metres / m) Based on the requirements of data for this experiment, the following setup has been derived. Preliminary
Theme Park visit report: The physics of roller coasters.
Theme Park Visit Report On the 11th October 2007, we visited Drayton Manor theme park. We set out to learn more about the physics involved in theme parks. Although there are many aspects of physics present in a theme park I have concentrated my effort on just two aspects in this report. The two aspects I have chosen are power and efficiency. Before I start calculating power and efficiency I have decided to explain the basic principles of a roller coaster as it helps when explaining the usefulness of knowing power and efficiency how they can be calculated and the equations to calculate them. Physics of the roller coaster. The purpose of a roller coasters initial ascent is to build up gravitational potential energy(fig.1). Once you pass over the crest of the initial ascent the built up gravitational potential energy of the cart is transferred to kinetic energy as you descend for the first time(fig.2). A force of 9.81 NKg-( is applied to the cart as this is the Earth's gravitational field strength which gives the cart an acceleration of about 9.81 ms-( as it falls towards the Earth. As Newton's third law states the conservation of momentum means that an object in motion retains momentum and in turn motion. So as the cart ascends up the second ascent it will retain motion(fig.3), but decelerates at 9.81 ms-( as it travels against the force of gravity converting it's
How can you explain the difference in times for a whole cup cake holder to fall compared to when it is screwed up into in a ball due to surface area, air resistance and mass?
How can you explain the difference in times for a whole cup cake holder to fall compared to when it is screwed up into in a ball due to surface area, air resistance and mass? Equipment * 6 cup cake holders * Metre Ruler * Stop Watch * Blue Tack Method We started by weighing a single cup cake holder, it being (0.2g.) We dropped it from a distance of 1.84m from the ground. We then recorded the time it took to fall. We then screwed it up and dropped it from the same distance to see whether surface area had an effect on the time. After the first experiment we started investigating mass as well by adding 0.2g of blue tack every time on 5 more cup cake holders, repeating the screwed up and non screwed up procedure. Fair Test This will be a fair test as it will be the same distance (1.84m) for each occasion and will be in the same condition room with no more or less wind. The Blue tack will be exactly 0.2g each time it is added onto the previous weight. Results Screwed Up Cup Cake Holder Mass (g) Time (s) 0.2 0.72 0.4 0.56 0.6 0.41 0.8 0.39 .0 0.33 .2 0.27 Non - Screwed Up Cup Cake Holder Mass (g) Time (s) 0.2 .47 0.4 .05 0.6 .03 0.8 0.84 .0 0.76 .2 0.66 Conclusion By carrying out this experiment I have learnt that surface area plays a great part on an object being dropped from a distance, even if the mass of the object is the same. The
Investigating how height affects time taken for a falling object to reach ground level.
PHYSICS COURSEWORK 2003: Investigating How Height Affects Time Taken for A Falling Object to Reach Ground Level. Introduction: In this investigation, how height will affect the time taken for a steel ball bearing to reach the ground will be investigated. It is was Isaac Newton that first discovered gravity and wrote laws defining it. His Second Law of Motion states that the Resultant Force on an object (F) is equal to the Mass of the body (m) times its acceleration (a), or . The weight (W) of a body is the force of gravity acting on it, which gives it acceleration (g) if it is falling freely close to the earth's surface. If the body was to have a mass (m) Newton's 2nd Law of Motion could calculate its weight. Given that and Newton's Law becomes . In April of 2003, in a method similar to that, which will be conducted in this investigation, the acceleration of gravity was concluded to be 9.81. Using the knowledge mentioned above, several equation of motion have been created. One particularly relevant to this investigation is . In this equation: S = Distance in meters (In this case height) u = Initial velocity in * t = Time Taken in seconds a = Acceleration in ** * As the ball begins its fall from rest, its initial velocity, u, will be 0 ** As the ball is falling under acceleration due to gravity, = 9.81 Plan: In this investigation, since the means to calculate
Tsiolkovsky, rockets and forces.
Tsiolkovsky was a hearing impaired Russian theorist and a great visionary. Tsiolkovsky was the first to establish theories regarding rockets with calculations to back them up. He was the first to calculate the escape velocity of the earth. He had a great imagination, foreseeing not only much of the development of rocketry and space travel to this point, but also developments beyond where we are today. In his mind rockets would carry people out to space stations and then on to the moon and mars. He predicted space suits, artificial gravity and terraforming. He never put his ideas to a practical test by actually launching a rocket; however he had many insights into how rocket design could be improved. He felt that liquid fuelled rockets would be preferable to solid fuelled rockets, since the thrust on a liquid fuelled rocket could be adjusted by varying the flow rate of the fuel. Tsiolkovsky also developed the idea of specific momentum for rocket fuels, the hotter and lighter a fuel is, the better the thrust for a rocket. He suggested that rockets should have stages to prevent them carrying excess mass. the best known is the theory of rocket flight which he developed from the laws of motion.3 In its simplest form, the velocity of a rocket can be expressed as: V = Vj ln(Mo/ Me) where V is the maximum velocity of the rocket in gravity-free, drag-free flight, Vj is the rocket
AS OCR B (Advancing Physics) - Data Handling
Physics Coursework Data handling The results I have been given are from a tensile strength experiment. In this experiment a piece of material; usually a wire would be hung with a varying weights attached to it and the amount by which its length increased would be measured. I am told the extension of the material and the force applied for 19 pairs of results. I am also told that the diameter is 0.45mm and the original length is 2m The results are as follows: Force(N) Extension(mm) 3 0.4 6 0.9 9 2 .2 5 .6 8 .8 21 2 24 2.1 27 2.6 30 2.8 33 3 36 3.1 39 3.3 42 3.5 45 3.8 48 4.1 51 4.1 54 4.4 57 4.8 The graph above shows how extension changes with increasing force. It shows what is expected; the extension increases when the force is increased. However this relationship is not directly proportional and the rate at which extension changes varies. However the extension never decreases so I can tell so far that there are no immediately obvious anomalies. Although at one point 48N and 51N the extension does not change but this is plausible because in the experiment the wire is held in with only two wooden blocks and this setup is liable to slippage of the wire in the blocks, so this would explain the anomalies. I have plotted force against extension, even though the independent variable is force, because of Hooke's law I am going to find out
D2 Measurong Young's modulus of copper(TAS)
D2 Measurong Young's modulus of copper(TAS) Objective In this experiment, The Young's modulus of copper will be mesured . Apparatus - copper wire 4m - G-clamp - polley on clamp -2*Wooden block - 2*rule (half meter and meter rule) - slotted mass with hanger 15 * 0.1 kg - adhesive label -micrometer screw gauge -safety goggles -polystyrene board (Warning : Wear safety goggles when doing this experiment ) Theory When a spring is stretched or compressed by a force.The extension is directly proportional to the applied force.This relationship known as Hooke's law. Force=ke.However,the law is used when the proportional limit is not exceeded.To further investigate how the material behaves when it is stressed,we define: The stress applied to the wire is defined as the force applied per unit cross-sectional area. Stress = force per unit area =F/A (where F is the force or tension in the wire, A is the cross-sectional area) When the wire being stretched,it is under strain.The strain is defined as the extension per unit length. Strain = extension per unit length = e/l (where e is the extension and l is the unstretched length of the wire) Withon the proportional limit,the ration stress/strain is a constant whose value depends on the material of the wire. It is known as the Young modulus of the material E = stress/strain = (F/A)/(e/l) = Fl/Ae From
"Consider how the police are depicted in 'The Blue Lamp' and 'Billy Elliot'".
"Consider how the police are depicted in 'The Blue Lamp' and 'Billy Elliot'". I shall begin my essay by studying several scenes in the film 'Billy Elliot', which was made in 2000, directed by Stephen Daldry. The main focus of this particular film is the 1984 miners' strike, a defining point in British history. Billy Elliot is a young boy of age eleven. He lives in a small and confined north-eastern mining district, where the majority of workers are currently involved in a violent strike as a form of forceful protestation. Billy lives with his elderly grandmother, as well as his older brother Tony and his father who are both connected with their striking miners maintaining a picket line against the strike-breakers. The first significant shot in the film, providing us with our initial view of the police, consists of Billy discovering that his grandmother has strayed out of the house they share. He runs into the nearby field, eventually finding and coaxing his absent-minded grandmother to return home. The police force are visible on a road above the field. The camera shot is a 'long-shot', focusing on the force's high position and great number, and therefore making the officers seem superior. The police are shown here to be a nameless, unknown body. It seems as though the habitants of the district are used to, and have become familiar with, the seemingly strong force