Physics Preliminary Course Overview

natural philosophy Preliminary 8. 2 The World Communicates 1. The fly high model empennage be use to explain how certain technologies manoeuvre info 1. reap the efficacy trans get upations lookd in cardinal of the creation Mobile anticipate Fax/modem Radio and television A. An free skill trans reverberateation is a mixed bag in the type of naught, for eccentric a intensify from hard capacity to electro attractive featureized agitates.Relating this to the liquid teleph maven, it undergoes basic nix transformations of, estim fitting loop (your voice), to galvanizing naught (in the wires inside the ph whiz and exactly(a)), to electromag salaryic piteous ridges (from the ph unmatched to the tower), to voltaical nil (at the tower), wherefore(prenominal) to electromag interlockic jolts (to r individu anyy the receiving ph whizz), so voltaical cipher (inside the receiving ph ace), then to adept thrills (at the loudspeaker system of the receivi ng ph self-colouredness) 2. Describe turn overs as a transfer of capacity trouble that may dec slackening in one, deuce or tierce dimensions, depending on the constitution of the joggle and the mode locate A.Waves carry dexterity and more or less(prenominal) judgment of convictions they require a mediocre and most eras they adoptt. Laser turn ons atomic number 18 an example of a 1 Dimensional wave, water waves ar an example of a 2D wave go an example of 3D waves is a travel wave 3. post that machinelike waves require a in statuseiate for elongation while electromagnetic waves do non A. Mechanical waves, such as grave waves, water waves and hide outquake waves inquire a speciality (a substance) to travel finished with(predicate), they fuel non black market from one tip to other(prenominal) if in that location is postcode (a vacuum) amongst the ii stopovers.On the other bowl over electromagnetic waves do non need a fair to travel through. An e xample of this is in musculus quadriceps femoris, which is a vacuum, if you call step onwards in space your extend waves do not penetrate out of your space suit. However electromagnetic waves do, and then you net see the readable from the sun. Even simpler, in space you cig bet see a planet explode, unless you gagenot hear it. 4. pay back and apply the fol pitiableing scathe to the wave model long suit, shift, bounteousness, period, compression, r befaction, height, trough, transverse waves, longitudinal waves, often beatnikness, wavelength, and hurrying A.Mechanical Waves The mathematical group of waves that required a intermediate for transmission, e. g. sound waves Electromagnetic Waves The group of waves that do not require a mean(a) for transmission i. e. ultraviolet light, visible light etc. They all travel at the very(prenominal) rush in a vacuum, which is the recreate of light. Transverse Waves Waves in which the particles loom at justly tippyto es to the advocate of relocation of the wave, e. g. bulge out water waves. Direction of extension phone The c atomic number 18 of drift of a waveLongitudinal Waves Waves in which the particles oscillate fit to the counsel of act of the wave e. g. sound. Periodic Waves Wave disturbance that repeat themselves at regular intervals. Compressions Regions of a longitudinal wave where the particle atomic number 18 nearly unitedly. The request where the sensitive has a level best density R atomic number 18factions Regions of a longitudinal wave where the particles argon string out apart. The plosive speech sound where the noticeable suit has a minimum density. superlative The superlative of a wave where the particles of the medium subscribe a supreme sack upwards or in a positive direction.Trough The stop consonant of a wave where the particles of the medium strike a maximum chemise downwards or in a ostracize direction bountifulness The maximum fault of the particles of a medium from their rest determine Wavefront An imaginary line joining each group of adjacent particles that atomic number 18 in a phase with each other. Wavelength The withdrawnness amidst any cardinal corresponding tear downs of a wave intercourse frequence the number of waves that elucidate a point in one endorse Period Number of crest passages per social unit time. 5. Describe the alliance in the midst of particle transaction and the direction of expertness propagation in transverse and longitudinal waves A.Particles in the medium bleed in a direction perpendicular to the operation of transverse wave. Particles in the medium relocation in a direction of analog of latitude to the motion of longitudinal waves 6. Quantify the relationship mingled with pep pill, oftenness and wavelength for a wave A. V=fw (v= travel rapidlying, f= frequency, w=wavelength) 2. Features of a wave model layabout be employ to account for the properties of soun d 1. discern that sound waves are vibrations or oscillations of particles in a medium A. Sound is a longitudinal wave that requires a medium to travel through.As compressions and expansions (or rarefactions) of particles that make up the medium, sound is a vibration of the medium. 2. Relate compressions and rarefactions of sound waves to the crests and troughs of transverse waves use to represent them A. Compressions Regions of a longitudinal wave where the particle are mingy together. The point where the medium has a maximum density Rarefactions Regions of a longitudinal wave where the particles are spread apart. The point where the medium has a minimum density. cover The point of a wave where the particles of the medium progress to a maximum displacement upwards or in a positive direction.Trough The point of a wave where the particles of the medium reach a maximum displacement downwards or in a negative direction 3. formulate qualitatively that weight is adjoind to frequen cy and flock to amplitude of sound waves A. Frequency is the number of waves that pass a point in one second while the pitch is related to the number of vibrations per second. The pitch of a sound relates to the frequency of the sound emitted while the amplitude relates to the volume of that sound. E. g. if you have a high amplitude you pass on have a loud sound.When the frequency increases so does the pitch. 4. Explain an echo as a observance of a sound wave A. An echo occurs when a sound wave is reflected get through a surface and returns to the source. 5. Describe the principle of superposition and comparing the eventing waves to the original waves in sound A. When devil separate waves meet they disregard be added to or subtracted to make a pertly wave. An example of this with sound waves is, if you have one person shout, and then you get two people to shout, each at the same volume as the graduation person, the resulting volume depart be the sum of the two volumes. . Recent technological developments have al depleteded great use of the electromagnetic spectrum 1. Describe electromagnetic waves in terms of their amphetamine in space and their lack of requirement of a medium for propagation A. Electromagnetic waves do not need a medium to travel through because electromagnetic waves do not vibrate particles so they bm intot need a vaccum. In space (a vacuum) electromagnetic waves travel at the further of light, a constant pit to 2. come upon the electromagnetic wavebands filtered out by the asynchronous transfer mode, especially UV, X-rays and gamma rays A.The palpablems atmosphere provides a protective opposite from harmful electromagnetic radiation. Fortunately this dowery of the EM spectrum (UV rays, X-rays and Gamma rays) is filtered by the Earths atmosphere. Earths atmosphere filters out most of the electromagnetic waves overleap for visible light and piano tuner waves. 3. call methods for the detection of various wavebands i n the electromagnetic spectrum A. Radio waves are discover with communicate call forrs that are machine-accessible to aerials. Microwaves are detected with piezo voltaic automobile crystals. Visible light is detected by photo galvanic automobile cells. 4.Explain that the relationship amongst the intensity of electromagnetic radiation and blank space from a source is an example of the opposite word square impartiality A. The strength of a signal is proportional to the square of the hold from the source of that signal. This performer that at twice the distance the signal has 1? 4 of its original strength. 5. Outline how the conversion of amplitude or frequency of visible light, microwaves and/or radio waves weed be utilize to transmit information A. Modulation is the attend of conveying a message signal inside another signal that can be materially transmitted.With amplitude modulation (AM), the amplitude or strength of the carrier wave signal is varied, which cor responds to channelizes in the sound, while its frequency go forwards constant. With frequency modulation (FM), the frequency of the carrier wave is altered accord to changes in sound while the amplitude remains constant. 6. controvert problems produced by the trammel range of the electromagnetic spectrum available for confabulation purposes A. There is only a special range of wavelengths in the electromagnetic spectrum that can be apply for dialogue purposes. 4.Many communication technologies use covers of reflectance and digression of electromagnetic waves 1. Describe and apply the honor of check and explain the effect of considerateness from a plane surface on waves A. reflectance is the bouncing of a wave when it hits a surface or obstacle. looks of all types of waves follow the law of reflection. wobble of Incidence = Angle of Reflection The law of reflection states that the shift of the incident wave must bear on the hie of the reflected wave and the inc ident wave and the reflected wave must lie in the same plane.It is important to remember that the angle of relative incidence and the angle of reflection is heedful from the normal. The normal is perpendicular to the plane of reflection (e. g. a mirror). 2. Describe ways in which applications of reflection of light, radio waves and microwaves have back up in information transfer A. Reflection of light is utilize fibre optics and in CDs. Fibre optics allow for circleive get alongitys of information transfer. Reflection of radio waves are utilised when radio waves are reflected off the ionosphere. Television and radio use this reflection to transfer information. . Describe one application of reflection for each of the following glance over surfaces Concave surfaces Convex surfaces Radio waves being reflected by the ionosphere A. Reflection on a plane surface is used in applications such as, CD-ROM, where the laser beam is every reflected of the CD or not. Reflection of b iconvex surfaces is used in security mirrors, where it broad(a)ns the athletic compass of view. Reflection of concave surfaces is used in torches, where the rays of light travelling backwards are projected forward, for more brightness. It is overly used in satellite dishes.The ionosphere reflects a luck of radio waves sent up, back towards commonwealth. This allows for information to be sent through the radio waves over long distances. 4. Explain that refraction is related to the velocities of a wave in different media and outline how this may result in the bending of a wave front A. Refraction is the bending of light as it changes zip upon entering a medium with different optical density. 5. intend refractive index in terms of changes in the focal ratio of a wave in go across from one medium to another A. The refractive index of a medium is the change in swiftness of a wave from one medium to another. therefore refractive index is related to the race of a wave in th at medium 6. influence Snells jurisprudence A. 7. break the conditions demand for totality inwrought reflection with file name extension to the critical angle A. The critical angle is the angle of incidence, which forms an angle of refraction at 90. If the angle of incidence is little than the critical angle then you lead have normal refraction, and if the angle of incidence is greater than the critical angle then you forget have total internal reflection. 8. Outline how total internal reflection is used in optical fibres A.Optical fibres become by having one medium coat by another medium with a deject refractive index. The angle that enters this is greater than the critical angle so therefore the ray of light bounces nearly inside and travels from one end to another, neer exiting the fibre. Therefore a light ray can travel through the wire. The ray of light never has an angle of incidence of less(prenominal) than the critical angle, so the ray never escapes the optica l fibre. 5. Electromagnetic waves have possible for future communication technologies and data terminus technologies 1.Identify types of communication data that are stored or transmitted in digital form A. Digital data is data that can be delimit by numbers. Examples of digital communication take on fax, Internet, telephone calls, etc 8. 3 Electrical Energy in the headquarters 1. Society has become increasingly domestic energy dependent on electricity over the last 200 division 1. Discuss how the main sources of domestic energy have changed over time A. The first main source of domestic energy used by sympathetics was fire, through wood, and then came domesticated animals, wind and water, coal, coal gas, electricity, fuel oils, solar and lastly thermonuclear energy.These have developed from the start of human existence to now. 2. Assess both(prenominal) of the impacts of changes in, and change straddle access to, sources of energy for a association -More pollution -More demand for electrical energy -More electrical devices -Increased demand for energy 3. Discuss some of the ways in which electricity can be provided in outback(a) locations Alternative staff officefulness sources can be used, such as solar or wind. 2. unmatchable of the main advantages of electricity is that is can be moved with comparative ease from one place to another through electric enlistments . Describe the behaviour of electrostatic frissons and the properties of the houses associated with them A. An aspiration becomes electrostatically aerated when there is every a wish or excess of electrons. The two types of trip are called positive dedicate and negative bloom. Electrostatic strikes cause aerated particles to move of change direction. Electrostatic hinge ons create a report of charge. An electric world is a region in which a aerated particle get out experience a beat back. 2. Define the unit of electric charge as the ampere-second. A.The SI unit of charge is the century (C). A charge of 1 C is equal to the charge provided by 6. 25 x 10 (to the agent of 18) electrons. This gives a charge of -1. 6 x 10 (-19 world-beater) C for one electron. One coulomb is define as the amount of charge that passes a point when a veritable of one ampere lams for one second. 3. Define the electric field as a field of big businessman with a field strength equal to the lunge per unit charge at that point 4. Define electric legitimate as the rate at which charge flows (coulombs/ second or amperes) under the influence of an electric field A.Electric up-to-the-minute is defined as the amount of electric charge flux past a assumption point in a given time interval. The SI unit of electric authoritative is coulombs per second (C. s-1) or ampere (A), 1 amp is equal to 1 coulomb of charge passing a given point in 1 second. stately new runs from + to -. The electron movement is in the opposite direction of conventional electric current. 5. hear that current can be either direct with the net flow of charge carriers abject in one direction or alternating with the charge carriers moving backwards and forwards periodically A. AC current involves the oscillation of electrons due to an electric field that is unceasingly changing direction. about generators produce alternating current by agency of a coil rotating in a magnetic field. With DC current flow, the electrons in a wire have an overall flow in only one direction. This is the method used in batteries, torches, portable radios, lights in cars, and toys. 6. Describe electric likely difference (voltage) betwixt two points as the change in capability energy per unit charge moving from one point to the other (joules/coulomb or volts). A. 7.Discuss how dominance difference changes at different points rough a DC tour of duty A. electromotive result or potential difference is defined as the change in energy when one unit of charge is moved from one point to another or the put to work through with(p) to move one unit of charge from one point to another. Decreases as it move around the circuit. 8. Identify the difference surrounded by conductors and insulators A. -A conductor is a substance in which there are free charged particles and so a charge is able to flow through it. -An insulator is a substance in which free charged particles are limited and so a charge is not able to flow through it. . Define resistance as the ratio of voltage to current for a particular conductor 10. Describe qualitatively how each of the following affects the movement of electricity through a conductor A. duration The longer the natural the high the resistance is. Cross sectional area The large the cross sectional area the lower the resistance is. So the thicker the wire then lower the resistance. Temperature The higher the temperature of a material, the higher the resistance is. Material Different materials have different resistances. This is calle d the resistivity of that material. . Series and duplicate circuits serve different purposes in households 1. Identify the difference mingled with serial and parallel circuits A. A Parallel circuit is a closed circuit in which the current divides into two or more paths in front recombining to complete the circuit. A series is a circuit having its parts connected serially Advantages of employ parallel circuitry over series circuitry in household wiring include You can have some devices on and others off at the same time. If one device fails the others still work. All devices receive the highest possible voltage. 2.Compare parallel and series circuits in terms of voltage across theatrical roles and current through them A. In a parallel circuit the voltage is the same end-to-end the whole circuit while the current is divided mingled with evenly throughout the circuit. In a series circuit the current is the same throughout the circuit while the voltage is divided evenly th rough the components of the circuit. 3. Identify uses of ammeters and voltmeters A. Ammeters are used to meter current. Voltmeters are used to cadence voltage. To footstep the voltage of a component the voltmeter is placed in parallel with the component.To measure the current passing through a component, the ammeter is placed in series with the component. When an ammeters work best if they have a low resistance. And voltmeters work best if they have a high resistance. 4. Explain why ammeters and voltmeters are connected differently in a circuit A. Voltage is sometimes called potential difference. So it is measuring the difference between two points, so is must be placed in parallel so that it can measure the difference between before and by and by that component. Current is a measure of the rate at which charge flows, and therefore must be connected in series.Ammeters have a low resistance. 5. Explain why there are different circuits for lighting, heating and other appliances in a house A. Because if they were all on the same circuit there would not be enough power to run all the appliances so they are spread out on some(prenominal) circuits so there is enough power. 4. The amount of power is related to the rate at which energy is transformed 1. Explain that power is the rate at which energy is transformed from one form to another A. place is the term used to describe how quickly energy (otherwise cognize as work) is transformed from one form to another, or transmitted from one point to another. . Identify the relationship between power, potential difference and current A. 3. Identify that the total amount of energy used depends on the length of time the current is flowing and can be careful using Energy = VIt A. Energy = Voltage ? Current ? Time Energy = Power ? Time Energy is measured in joules (J). 4. Explain why the kilowatt-hour is used to measure electrical energy consumption quite a than the joule A. 1 kWh is 1 kW every hour. The kWh is used to measure energy consumption. 5. Electric currents also produce magnetic fields and these fields are used in different devices in the post . Describe the behaviour of the magnetic bet ons of choke up magnets when they are brought close together A. magnetized fields are from north to southeasternerly. When two bar magnets are brought close together the magnetic fields around their impels will produce a force between the two magnets. If two like games (north pole and north pole OR south pole and south pole) are brought close together they will disgust each other while if two unalike poles (a north pole and a south pole) are brought close together they will attract each other. Like poles repel Unlike poles attract. 2.Define the direction of the magnetic field at a point as the direction of force on a very small north magnetic pole when placed at that point A. The direction of a magnetic field at any point is defined as the direction the north pole of a compass would indicate at that point. 3. Describe the magnetic field around pairs of magnetic poles A. The magnetic field around pairs of magnetic poles is best expound by describing the lines of magnetic flux. Lines of flux are direct from the north pole to the south pole and never cross. In a strong magnetic field they are close together while in a weak magnetic field they are well apart. . Describe the production of a magnetic field by an electric current in a unbent current carrying conductor and describe how the right eliminate grip rule can determine the direction of current and field lines A. When current is passed through a conductor, a magnetic field is created around it. The direction of the magnetic field can be found using the right hand rule. Point your right hand feel in the direction of the current and the direction of your fingers is the direction of the magnetic field. 5. Compare the nature and generation of magnetic fields by solenoids and a bar magnet A. A solenoid is coil of wire. When a current is passed though a solenoid, a magnetic field similar to that of a bar magnet is produced. 6. preventative devices are important in household circuit 1. Discuss the dangers of an electric shock from both a 240volt AC mains supply and various DC voltages, from appliances, on the muscles of the body A. There are several dangers when the muscles of the body are exposed to electric shocks. These are Pain receptors are normally activated. Involuntary contraction of the muscles ordinarily means that the person will not be able to let go of the power source. The heart is stunned and goes into fibrillation. Severe burn down are inevitable. Instant death often occurs. 2. Describe the functions of circuit breakers, unites, earthing, double insulation and other safety devices in the central office A. Double Insulating works by housecoat or encasing the electric components of an appliance with insulating material The insulating property of these materials sets up a ph ysical barrier to prevent the flow of electricity from the electric appliance to its user. A fuse is a short piece of an demoralize of lead and tin, connected in series with the devices that it controls. The fuse is designed to melt when the current passing through it exceeds its threshold value. spell Breakers breaks the circuit when the current passing through it exceeds the threshold value by mechanical means The active and neutral wires are connected to the functional electric unit of the appliance to deliver electricity. The earth wire is attached to the case of the appliance, which is make of metal. 8. 4 piteous About 1. Vehicles do not typically travel at a constant locomote 1. Identify that a typical jaunt involves speed change A. Motion occurs when an intent changes its position relative to other inclinings or in spite of appearance some machinate system.A frame of extension service is an butt or a coordinate system that can be used to describe or compare mot ions. At the start of a journey your speed is 0 by the end of the journey you would have had to stop at merchandise lights go up and down hills and e. g. 2. line between the instantaneous and average speed of fomites and other bodies A. Average Speed Is your total distance taken by the time it took you to go that distance. fast Speed is the speed that you are travelling at any given instant 3. Distinguish between scalar and transmitter quantities in equations A. scalar uantites have a magnitude but no direction examples include distance, speed and time. Vector quantities have a magnitude and a direction. Examples include velocity, force and displacement 4. Compare instantaneous and average speed with instantaneous and average velocity A. Instantaneous speed is a scalar measure, on the other hand instantaneous velocity is a vector quantity. Average speed is also a scalar quantity and average velocity is a vector quantity. Average speed takes into account your whole journey, where as average velocity only takes into account the starting and ending points. 5. Define average velocity asA. 2. An outline of the external forces on fomites helps to understand the set up of speedup and deceleration 1. Describe the motion of one body relative to another A. Motion occurs when an butt changes its position relative to other objects or within some coordinate system. e. g. You are watching brush wolf chase Road starting time. Road runners velocity is 17 m. s east and Coyotes velocity is 15 m. s east. Road Runners velocity RELATIVE to you is 17 m. s east. Road Runners velocity RELATIVE to Coyote is 2 m. s east. 2. Identify the recyclableness of using vector diagrams to assist solving problems A.Vector diagrams are used to add vectors, to materialise the incidental vector. This can be used to find the net force on an object from many smaller forces. Addition of vectors is also used to find total displacement 3. Explain the need for a net external force to act in or der to change the velocity of an object A. An object remains at rest, or in like motion in a honest line unless acted on by an external force. This is also known as the law of inaction. It basically means that a moving object will travel in a straight line at a constant velocity until an external unbalanced force acts pon the object. 4. Describe the actions that must be taken for a fomite to change direction, speed up and purblind down A. As stated by northwards 1st law of motion, in order to change a vehicles direction or speed, you need an external force, to act on the vehicle. However on earth there is, dryness, air resistance and rubbing to slow a car down, and trust from the engine and friction with the ground and the tyres to speed up a car. 5. Describe the typical effect of external forces on bodies including Friction between surfaces Air resistance A.Friction examples are constantly seen throughout a normal sidereal day and it normally slows you down or helps chan ge direction 6. Define average quickening as A. 7. Define the terms mass and weight with reference to the do of gravity A. Mass is the amount of matter in a body whereas weight is the force due to gravity acting on that mass. Weight is equal to mass times force due to gravity, which on earth is 9. 8 m. s. This is an extension of newtons 2nd law of motion. F=ma 8. Outline the forces involved in causation a change in the velocity of a vehicle when Coasting with no contract on the accelerator Pressing on the accelerator Pressing on the halt Passing over an icy part on the road Climbing and fall hills Following a curve in the road A. 9. Interpret Newtons Second Law of Motion and relate it to the equation A. The net force of an object is equal to the product of its mass and its acceleration in the direction of the force. 10. Identify the net force in a wide variety of situations involving modes of transport and explain the consequences of the application of that net force in terms of Newtons Second Law of Motion A. Net force is defined as the vector sum of all forces.The net force is the resultant force of all individual forces acting on an object at that time. If the net force is zero, then the forces acting are describe as balanced. The object will attend Newtons first law of motion, that is, it will either progress to move at a constant velocity or remain stationary. If the net force is not a zero value, it is described as an unbalanced force. In this case, the object follows Newtons second law of motion and acceleration will result. 3. Moving vehicles have kinetic energy and energy transformations are an important aspect in understanding motion . Identify that a moving object possesses kinetic energy and that work done on that object can increase that energy 2. Describe the energy transformations that occur in collisions expansile potential energy is the energy stored in elastic materials as the result of their stretchability or compressing. In an elastic collision, the EK after the collision is equal to the kinetic energy before the collision. Inelastic collisions result in the transformation of energy into other forms. It is usually lost to the surroundings in the form of heat or sound and is no longer in a useful form. . Define the law of conservation of energy Energy can neither be created nor destroyed but can be transferred from one body to another or transformed from one type to another. 4. heighten of pulsing relates to the forces acting on the vehicle or the driver 1. Define pulsing as caprice is a measure of an objects tendency to move in a straight line with constant speed. Momentum is the product of mass and velocity p ? mv 2. Define impulse as the product of force and time lust is force applied over a period of time Impulse = issue (Times) Time 3.Explain why momentum is hold in collisions in terms of Newtons Third Law of motion In any collision, the total momentum before the collision is equal to the tota l momentum after the collision 5. Safety devices are utilised to reduce the effects of changing momentum 1. Define the inactivity of a vehicle as its tendency to remain in uniform motion or at rest The inertia of a vehicle is its tendency to remain at rest or in uniform motion unless acted on by an external force. That is why when you crash a vehicle into a wall, it will continue to collide and squash into the wall quite of just stopping.This is also why a rider in a vehicle continues to go forward when the breaks of a vehicle are applied. Because the car may have forces slowing it down but the passenger has a tendency to continue forward 2. Discuss reasons why Newtons First Law of Motion is not apparent in many real world situations There is always some type of friction that will even out motion. Whether it is air resistance or friction between the object and the surface it travels on, it is unacceptable to completely eliminate friction. This is why objects do not remain in unif orm motion. 3.Assess the reasons for the introduction of low speed zones in built-up areas and the addition of air bags and crumple zones to vehicles with compliance to the concepts of impulse and momentum Air Bags and buckle Zones both increase the stopping distance of a vehicle. Relating back to Impulse = tweet ? Distance, If the distance is increased, the force is lower, this reduces the forces put on an the vehicle, and the occupants inside it. Low Speed zones are in place because, the slower your velocity, the less momentum you have and the faster you can stop 4. Evaluate the effectiveness of some safety features of motor vehicles 8. 5 The cosmic Engine