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AS and A Level: Modern Physics
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- Peer Reviewed essays 4
1922 (17 years after Einstein first proposed the idea, and 1 year after he received the Nobel prize for his work on photoelectricity) that the idea was ?quite irreconcilable with so-called interference phenomena [and] not able to throw light on the nature of radiation? (Helge Kragh 2012 ). This statement also paved the way for the theories of wave-particle duality, which is the basis for almost all Quantum Mechanics. When I read about this I couldn?t really help but think how smug Einstein would have been when energy quanta was accepted by the scientific world (18 or so years after he first proposed the idea), for him to just know he was that far ahead of the rest of physics.
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It is safe to say that mobiles have taken over, making it impossible to travel without hearing a dull-tone version of the number 1 tune blasting in your ear followed by, "Hello? I'm on the train!" There are many stories of lives being saved when someone suffers a heart attack whilst in the middle of nowhere and the victim is rescued because their companion rang the emergency services on their mobile. This is one reason why so many people own mobiles - security.
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The History of Atomic Theory. Due to the constantly developing scientific theories, the model of the atom has changed significantly over the years from Democritus with his views of indivisible tomos to Thomsons plum pudding model and scientists3 star(s)
However, by then the number of elements had grown from 4 and included substances such as 'potash,' 'soda' and 'lime,' with none of the Greeks' elements remaining. During experiments with cathode rays around the turn of the 20th century, JJ Thomson discovered the electron. He realised that these cathode rays were a stream of particles and that they all had negative charges and small masses. They could also be deflected by electrical fields and magnets and Thomson concluded that the atom was further divisible, disproving the theory of Dalton and the Greeks.
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Many people claim that they do damage to people near the masts, however the modern world may not be able to function without the communication link provided by mobile phones. Radio Waves Properties: - Highest wavelengths of the electromagnetic spectrum, generated by all electrical goods, generated when an electron changes its spin on a molecule. Uses: - Transferring information without wires, radar, navigation, interstellar probes (radio waves that exert small magnetic forces like a 'tractor beam' have been proposed as a form of propulsion.) Dangers: - There are no direct dangers involved with radio waves but information can be intercepted.
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The development of the modern concept of the atom, the size and nature of an atom and the ideas on sub-atomic particles
Some of Dalton's points are still thought to be true, but over time this original theory has been modified. The first of these modifications came in 1897 when J.J. Thomson discovered the electron. Based on the work of William Crookes and his "Crookes tube" (Cathode-ray tube), Thomson discovered a negative charged particle was the cause of the light produced by the cathode-ray tube. He also discovered that these particles are present in all elements. These cathode-ray particles are now known as electrons.
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Geophysics case study - I will explore techniques used by people (primarily archeologists), to explore the areas of ground prior to archaeological research and excavation occurring
In this case, the radargram has been used on a site in Alabama, USA and the hyperbolic (curve shaped) lines show reflections off media, possibly hinting at a human burial site.i 2) Another method of determining the condition of area for archaeological research is the use of a range of survey methods; different survey methods respond to different physical properties. For instance using magnetic, metal (metal detectors etc) or can allow scientists to infer whether mineral deposits lay within the ground: ii Electrical resistivity is another type of surveying method; this method uses electricity which is surged through electrodes embedded on the ground surface; subsequently information on the depth and density of the ground is collected by twin 'potential'
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Whereas, the grey line is showing us the unstretch, so when we are removing the force individually. Notice, how this time, the line doesn't match the blue line; this is because energy is lost through heat and sound when stretching, so the extension will be a bit more. This means that the graph did not obey Hooke's law. As you can see on the graph, the area between the 2 lines represents lost energy. This type of graph is called the elastic hysteresis loop. This shows that the rubber was harder to stretch when loading rather than unloading, because more energy was required when loading, because the energy was lost as heat and sound.
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This is just a hypothetical theory but if true, an extra particle called the Higgs boson should exist. A disturbance in the Higgs field is in actual fact a Higgs boson. When particles interact with the Higgs field they cause a clustering effect and thus, gain mass. The more massive the particle the more it'll interact with the Higgs field and according to the Higgs mechanism, the more mass it will acquire. Many experiments around the world have illustrated Higgs' ideas but the presence of one mysterious particle has been predicted. Although years of work have established 'The Standard Model', they have also predicted the existence of an unknown particle, named today as the Higgs particle.
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All the four power stations in Hong Kong produce energy through fossil fuels such as coal, natural gas and diesel gas. The Guangdong Nuclear Station produces energy by means of uranium, while the Guangzhou Pumped Storage Power Station just acts as storage. Very unfortunately, nearly all of the energy sources in Hong Kong are non-renewable, and they will run out in the future. How non-renewable energy generate electricity Fossil fuel Fossil fuel is used indirectly to produce electricity. Fossil fuel is burnt to heat water in a boiler and convert it to steam which inturn rotates a turbine like in windmills.
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The reaction of which is expressed as: Fusion occurs when light nuclei are fused together, such as Hydrogen isotopes, Deuterium and Tritium; this reaction produces a helium nucleus and a single 'fast' neutron, with a combined energy of 17.6 MeV. The nucleus contains positively charged protons and neutrons with no charge but a similar mass. The positively charged protons repel the neutrons but the strong nuclear force is stronger and so holds the nucleus together. The mass of the nucleus is less than the sum of its parts (nucleons).
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One from the "Great Dane", Niels Bohr, "Anyone who is not shocked by quantum theory has not understood it." And lastly one from the Richard Feynman, "I think it is safe to say that no one can understand quantum mechanics." Generally quantum phenomena can only be observed in atomic and sub-atomic scale, it is rare to see such observations on a large scale. Of the various interpretations of quantum theory that have been proposed, most physicists accept the Copenhagen Interpretation, however this does not mean it does not have any faults or lead to any paradoxes.
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There are 50 evenly spaced markings around the thimble each representing 0.01mm since the spindle moves 0.5mm with every rotation of the thimble. The barrel also has evenly spaced markings each representing 1mm. When we measured the ball bearing, the markings on the barrel showed the diameter to be 10mm and the thimble at 0.00mm. The diameter of the ball bearing is 10.00mm correct to one hundredth of a millimetre and so the radius, r, is 5mm. Preliminary A ball bearing was dropped into honey of four different temperatures, being cleaned and dried between each, the time taken for the ball to fall 10cm was recorded.
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and is in the same direction, this would be difficult however as the force on the jumper is not the same throughout the jump, the tension varies with extension. Instead we could use energy conservation. The jumper will lose and gain energy in different stages of the jump. When the jumper reaches the very bottom of the jump his kinetic energy is '0'. This energy gets transferred to the chord as it stretches giving it elastic energy (Eel). 'Energy conservation tells us that the GPE lost must be equal to the elastic energy gained by the rope' (Salters Advanced Physics AS)
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In this case to check for contamination/purity of essential oils, but also mixed sugar concentrations. Different solutions exhibit characteristic polarisation angles and can only pass through in two planes - 90o to one another. Light is made up of Electro-magnetic waves of many different waveforms (incoherent). When directed through a plane, only that specific waveform of the light can pass through, this light has been polarized. A sugar solutions concentration is a very specific characterisation and rotates the plane polarized light a specific amount.
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At the start of the graph, there is a gradient of 9.6 s m-1, but when the distance is approximately 0.8 m, the gradient becomes significantly less at 1.5 s m-1. As the distance increases, the gradient of the graph decreases. This suggests that the average speed of the ball bearing is increasing. Gradient = ?y / ?x = t / s c = s / t 1 / c = t / s This would be due to the fact that with a higher distance, there is more time for gravity to accelerate the ball bearing.
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The way that the x-rays work is that if too much x-rays get through it shows that the can has too little beer contained within it. On the other hand if the can has just the right amount of beer within it only a few x-rays will be able to pass through. The reason that gamma rays weren't used is that the beer wouldn't stop the gamma rays passing through, so it would be completely useless in telling how much beer is in the can.
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Replace the Crookes' tube with the tube containing the electric plates and connect the terminals of the plate to its high DC voltage supply. Observe the effects of the electric field on the cathode rays. 4. Connect the tube with the fluorescent screen display to the induction coil and record the effect of placing a set of bar magnets around the cathode rays. 5. Finally, attach the tube containing the paddle wheel on tracks to the induction coil and observe the effects that the cathode rays have on the wheel when the tube is horizontal.
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A2 OCR B Advancing Physics Coursework - Research and Report - The development of a Theory of Gravity
Gravity alone remains outside this model. 1.2 What's wrong with Gravity? The problem with Gravity is that through the development of its theory, its existence in situations of different scale is neglected. Newton proposed the first, classical, theory of gravity - but it failed to address some things - allowing crucial prediction but never offering an answer to why or how the universe worked like this. Einstein explained that Newton could provide only an approximation, revolutionising understanding with the theory of General Relativity. But he couldn't explain what happened at a subatomic level, which is where quantum mechanics is applied.
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1: Positron being released in a cloud chamber Positron The electron is a lepton with a charge of -1 and with a negligible mass when compared to the hadrons. It is often represented as or . However, as a particle, the electron must have a corresponding antiparticle; and it does! It is called the positron and is written as , namely as an electron with a positive charge. Although the idea of a positive electron had been around for a while before then (the earlierst recorded reference was by Bragg in 1910 speculating about "bound-positive electron pairs"), the idea of
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Colour: Light yellow to a reddish brown (in heartwood). Workability: good Durability White pine tends to be very soft. This may make it unsuitable for some furniture applications. Uses Furniture, moldings, plywood, boat building, carpentry, veneer. Price inexpensive Pine is not the only type of wood that can be used for making toilet seats other popular choices are mahogany and oak. These are far more expensive but have a more luxurious feel about them and are less prone to dent or scratch. Oak is far more durable and can stand the test of time longer then pine.
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This will therefore toughen the glass and increase its compressive strength. Annealing glass www.americanglassresearch.com%2Fcontentmanager Tempered glass Toughened or tempered glass is glass that has been processed by controlled thermal or chemical treatments. It is a far more increased strength compared with normal glass and is used as it will usually shatter into small fragments, rather than sharp shards, when broken. This will make it far more safer when used for mass production. Tempered glass is strong, has enhanced thermal resistance, and breaks into small cuboid fragments rather than irregular shards of glass and therefore is less likely to cause injury.
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* Also, the number of electrons that each of the atom donates. The more electrons donated then the stronger the bond. Metallic Bonding http://hrsbstaff.ednet.ns.ca/dawsonrj/11%20Chem/Chapter%20notes/Chapter%208%20notes_files/image001.jpg Metals that consist of metal cations and they have a balancing number of free electrons also have unit cell structures. These types of metals are known to be crystalline structures which can also be described as either: * Body Centred Cubic (BCC) * Hexagonal Close Packed (HPC) * Face centred Cubic (FCC) http://ece-www.colorado.edu/~bart/book/bcc.gif http://ece-www.colorado.edu/~bart/book/fcc.gif http://www.everyscience.com/Chemistry/Inorganic/Ionic_Solids/.images/hcp_unitcell.gif Properties of metals.
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and in the opposite direction of the force on earth the resistant force is delivered by the ground beneath our feet, so if the ground was taken away, as in freefall, there would be no resistant force and we would not experience weight, that is what is meant by the term weightlessness. This is used in the ride I am going to study to create the feeling to falling into a pit and thus creating a thrill. Stopping forces Another physics principle I am going to explore is the use of forces to ensure that the ride is safe, specifically stopping forces.
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Bits vs qubits Consider first a classical computer that operates on a 3 bit register. At a given time, the state of the register is determined by a single string of 3 bits, such as "101". This is usually expressed by saying that the register contains a single string of 3 bits. A quantum computer, on the other hand, can be in a state which is a mixture of all the classically allowed states. The particular state is determined by 8 complex numbers. In quantum mechanics notation we would write: where a, b, c, d, e, f, g, and h are complex. Let us consider a particular example: State Amplitude Probability * (?+i �) (|?|2+|�|2)
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It's a possibility, even though at present the clear evidence suggests that if there is any effect on human health at all, it is a very, very low risk for the individual user However some studies have caused concern in the media. For example, in March, 2003 a study in the International Journal of Oncology suggested that mobile phone users had a 30% increased risk of brain tumours- mainly accoustic neuromas- that occurred close to the ear used for mobile phone listening.
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