Modern Physics - AQA GCE Physics B - Revision Notes

Music and sound * All sounds are formed by a vibration and require a medium to travel through. Sound travel as a longitudinal wave (compression waves) where it forms a series of compression (region of higher pressure than surrounding) and rarefaction (region of lower pressure than surrounding) * Distance between 2 compressions is one wavelength and the frequency is number of waves / compression passing a certain point per second - measured in Hertz (Hz). Wave speed (c) = frequency (f) x wavelength (λ) * Typical human ear can detect frequency ranging from 15 – 20000 Hearts. The frequency below this range is called infrasound and those above are ultrasound. * When sound is turned into electrical signal (i.e. recorded by a microphone) the frequency can be measured with an oscilloscope, here: Frequency = and vice versa, Time period = * The pitch of a sound is produced form the fundamental frequency (lowest frequency when it’s vibrating freely) plus harmonics (multiples of the fundamental frequency). * When hearing sound waves of certain pitches together it produces consonants or harmonics. These sound waves form the basis of a musical interval. I.e. any 2 musical not of frequency ratio of 2:1 are separated by an octave. Whereas 2 notes with frequency ratio of 5:4 are separated by an interval of a third. * Quality can be called timbre. The same frequency note

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A2 OCR B Advancing Physics Coursework - Research and Report - The development of a Theory of Gravity

The development of a Theory of Gravity. What's behind it and where does it stand in relation to the other forces? Abstract: The Theory of Gravity has been transformed through the last century, from an original and important classical framework to more recent relativistic and then quantum interpretations, eventually culminating in a specific requirement to link it all together with the other forces and create a unified theory of everything. The search for unification is currently very much dependent upon experimentation and raises questions as to the scientific validity of String Theory and whether it exists as science or philosophy - or indeed just an elegant, but meaningless, example of mathematical aesthetics. . Introduction The ultimate goal for physicists is to devise a unified theory, which describes the universe all in one go. However, this proves difficult - there are partial theories which do not fit together, each predicting a limiting number of observations and neglecting others. Nevertheless the Standard Model exists as a framework for the coming together of partial theories. .1 The Basics of the Standard Model In matter there appears to be four basic forces at work. Gravity is the weakest of the four but acts over great distances, binding stars and galaxies together. The electromagnetic force is stronger and is responsible for holding atoms and molecules

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What are Quantum Computers?

Introduction What are Quantum Computers? Quantum computers have the potential to perform certain calculations billions of times faster than any silicon-based computer. Scientists have already built basic quantum computers that can perform certain calculations; but a practical quantum computer is still years away. Computers have become more compact and considerably faster in performing their task, the task remains the same: to manipulate and interpret an encoding of binary bits into a useful computational result. A bit is a fundamental unit of information, classically represented as a 0 or 1 in your digital computer. Each classical bit is physically realized through a macroscopic physical system, such as the magnetization on a hard disk or the charge on a capacitor. A document, for example, comprised of n-characters stored on the hard drive of a typical computer is accordingly described by a string of 8n zeros and ones. Herein lies a key difference between your classical computer and a quantum computer. Where a classical computer obeys the well understood laws of classical physics, a quantum computer is a device that harnesses physical phenomenon unique to quantum mechanics to realize a fundamentally new mode of information processing. In a quantum computer, the fundamental unit of information (called a quantum bit or qubit), is not binary but rather more quaternary

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Prove or conversely disprove the inverse square law.

Introduction My aim of this experiment is to prove or conversely disprove the inverse square law, which simply states that the intensity of any point source, which spreads its influence equally in all directions without a limit to its range, will decrease in intensity inversely proportional to the square of the distance. Background information Research As first proposed by Isaac Newton when proposing his universal law of gravitation it became clear to him that the intensity of gravity would decrease according to the inverse of the square of the distance. This is the heart of the inverse square, which states for any point source, which spreads its influence equally in all directions without a limit to its range, will obey the inverse square law. Quite simply the inverse square law states that for sources emitted from a point the intensity will be deduced as the inverse of the square of the distance. You double the distance you reduce the intensity by a factor of 1/4. This has applications in electric fields, light, sound, gamma radiation, and gravity. All of these are expressed in the medium of a field. To explain the properties involved in a field it is useful to use the idea of flux. When water flows form a 'source' to a sink it is transferred at a certain rate, or flux. The flux density will be the mass of water per second crossing a unit area

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Is it worth creating antimatter?

Is it Worthwhile creating antimatter? ANTIMATTER 3 WHAT IS ANTIMATTER? 3 SPECIFIC TYPES OF ANTIPARTICLES 3 POSITRON 4 ANTINUCLEONS 4 CREATIONS AND DESTRUCTIONS 5 BETA RADIATION 5 NEGATIVE BETA RADIATION 5 POSITIVE BETA RADIATION 6 POSITRON-ELECTRON ANNIHILATION 7 HOW DO WE STORE AND CREATE ANTIMATTER? 9 CURRENT ANTIMATTER PRODUCTION 9 PRODUCTION OF ANTIPROTONS 9 ANTIMATTER ATOMS 10 PENNING TRAP 10 USES OF ANTIMATTER? 13 ENERGY PRODUCTION 13 MILITARY WEAPONRY 15 MEDICAL IMAGING 16 PRODUCTION OF POSITRONS 16 IMAGING 16 IS IT WORTHWHILE CREATING ANTIMATTER? 17 CONCLUSION 17 IS IT WORTH CREATING ANTIMATTER NOW? 17 IS IT WORTH FUNDING RESEARCH INTO ANTIMATTER? 17 APPENDICES 18 APPENDIX A: TABLE OF FIGURES 18 APPENDIX B: BIBLIOGRAPHY 19 APPENDIX C: SYNOPTIC LINKS 20 Antimatter What is antimatter? For each of the fermions (leptons and quarks) detailed above, they have a corresponding anti-particle. These particles are in no way different to ours, except for the opposition of charge. In essence, there is no reason why our universe couldn't have been made from antimatter, and if it were, then we would classify our normal matter as antimatter. What this means is that antimatter merely has the anti prefix because it is not what we are used to. There is no deep meaning to it. For each elementary fermion, therefore, there is a corresponding antifermion.

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How temperature affects the viscosity of honey

HOW TEMPERATURE OF HONEY AFFECTS VISCOSITY Introduction Viscosity is a factor controlling resistance to flow and the speed that liquids flow is down to this. The lower the viscosity, the runnier the fluid is. Viscosity can be easily measured using the line spread test, how far and fast a fixed quantity of liquid spreads across a flat surface. Another way is by using George Gabriel Stokes' method of a falling ball, this method includes timing a ball falling at a constant rate (its terminal velocity) through a substance, the longer it takes for the ball to fall a measured distance the more viscous the substance. I am investigating how temperature affects the viscosity of honey, in order to do this I must use the falling ball viscometer method first conducting a preliminary experiment to find a suitable range of temperatures of honey to time a ball falling through. Archimedes stated: 'When a body is partially or totally immerse in a fluid, the upthrust is equal to the weight of the fluid it displaces.' When terminal velocity has been reached by the ball bearing the forces acting upon it will be balanced and the ball bearing will fall at a constants velocity. The magnitudes of these forces are related: Or: This equation can be rearranged by cancelling common factors of ? and r, multiplying by 3 and ten dividing by 2 to give: ? can then be made the subject: [Salters

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Investigating The Efficiency of Sun Block Cream.

Investigating The Efficiency of Sun Block Cream Aim of Investigation: The aim of this investigation is to discover how efficient sun block cream is and whether the claims by the company agree with my results. Why I chose this experiment: I chose to do this experiment because it seemed more interesting to me. Rather than just testing a sensor I thought it would be more interesting and rewardable to use a sensor to test something else. Also sunburn can be very serious and can cause illness therefore it is important to have efficient sun cream to prevent sunburn. What I am doing: I am going to take a range of factors of the same brand of sun cream and measure the level of UV radiation, which is allowed through each. It would also be good to test different brands as well however I could not obtain enough different brands of sun cream to carry out an experiment like this. What is UV radiation? The decrease of the ozone layer in the upper atmosphere, which serves as a protective shield against ultraviolet light, has focused much attention on the harmful effects of ultraviolet light (especially ultraviolet-B light). For example ultraviolet-B (UVB) light has harmful effects on the growth of agricultural crops, on the composition and constitution of ecosystems in the oceans and also on animal and human health, particularly for the skin and eye. Increased exposure to

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Bungee Jumping

Bungee Jumping Bungee jumping originated hundreds of years ago in New Guinea. Men leaped from very tall wooden towers attached to the tower by vines tied to their ankles, it was originally used as a test of courage but has since been converted into a recreational activity and is seen to be a once in a lifetime thrilling experience. The sport is simple yet exciting; jumping from a tall platform i.e. a bridge or a crane whilst attached to a length of elastic chord. A lot of calculations must be done before a bungee jump to ensure the safety of the jumper. The chord must be exactly the right length to give the best (yet safest) possible experience. If the chord is too short the jumper may not feel the optimum thrill however if the chord is too long it would probably result in the jumper being killed as they would hit the floor (go splat). I am going to do an experiment in order to find the exact height a fixed weight figure would need to jump from - with a certain length chord - in order to stop them just before they hit the ground. One way to try to work out the correct launch height would be to use the laws of motion; The rate of change of momentum of a body is proportional to the resultant force acting on the body and is in the same direction, this would be difficult however as the force on the jumper is not the same throughout

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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

Assignment 1 The development of the modern concept of the atom, the size and nature of an atom and the ideas on sub-atomic particles Introduction Throughout the ages the study of what we call today chemistry has evolved into a highly developed point of study. One distinct element of chemistry is atomic theory. Throughout the ages atomic theory has been developed and extended by many different men who were all well-known chemists and physicists in their day. They developed the study of atoms from pure conjecture into known facts. The five atomic theories of the past two centuries represent the sudden advancement of science in modern times. Beginning with a basic theory on the behavior of atoms to the current model, some changes have been made, and some ideas are still the same. Ancient Greek philosophers believed that everything was made up of invisible particles called atmos. Since then the theory of atoms did not progress until 1803. John Dalton was the first scientist to compose a theory of matter base on atoms. Dalton's atomic theory is based on four concepts. He stated: "1. All elements are composed of atoms, which are indivisible and indestructible particles. 2. All atoms of the same element are exactly alike; in particular, they have the same mass. 3. Atoms of different elements are different; in particular, they have different masses. 4. Compounds are formed by the

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A2 OCR B (Advancing Physics) - Research and Report: Nuclear Fusion as an Energy Source

Nuclear Fusion as an Energy Source In this project I am going to look at Nuclear Fusion as an Energy Source to replace dwindling fossil fuels, unreliable renewable energy and Nuclear Fission which produces hazardous waste. I shall investigate how efficient Nuclear Fusion is compared to these alternatives. I will also consider how safe Fusion is; including the reaction that takes place and any waste produced. I am also going to compare the advantages and disadvantages of Fusion with Fission and the other alternatives. Furthermore I will look into the current stage of development of Fusion to evaluate how likely it is that Nuclear Fusion can be used as an energy source in the future Nuclear Fusion is a process that occurs naturally in the sun (and other stars) and provides it with the tremendous energy it gives off. This gives it the potential to provide an almost limitless supply of clean energy for future generations. In Stars there are two chains of reactions which convert hydrogen to helium; the proton cycle and the Carbon-Nitrogen-Oxygen Cycle. The Proton cycle in the most common and occurs in our Sun. The reaction produces 27 MeV of energy but the reaction rate is very low, however the tremendous conditions on the Sun; 10-15 Million °C, 1/4 of a trillion atmospheres and 8 times the density of gold, allows matter to be converted into great amounts of energy. To make

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