Waves.Aim To find out whether drop height, depth or both affect the speed of a wave.
Science Coursework Waves An introduction to waves Mechanical Waves are waves, which propagate through a material medium (solid, liquid, or gas) at a wave speed, which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. The particles simply oscillate back and forth about their individual equilibrium positions. In a transverse wave the particle displacement is perpendicular to the direction of wave propagation. The particles do not move along with the wave; they simply oscillate up and down about their individual equilibrium positions as the wave passes by. Stacey Owen Candidate no: 0126 Hampton Community College Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases. If the radius of the circles decreases, this means that the wavelength of the wave increases. If the wavelength increases, the speed of the wave therefore increases. The speed of the wave is directly proportional to the wavelength. Aim To find out whether drop height, depth or both
refractive index prac report
Refractive Index Prac Report Aim: To find the refractive index of the Perspex block Hypothesis: The refractive index of the Perspex block should be grater than the refractive index of Air. Introduction: Snell's law states that the refractive index of a substance multiplied by Sin of the angle or incidence should be equal to the refractive index of another substance multiplied by Sin of the angle of refraction. The mathematical equation that describes this relationship is: Independent Variable: changing the angle of incidence ( 0) Dependant Variable: The angle of refraction Constant: The distance the light ray is placed away from the Perspex block to minimise error and the fading of the light ray. Materials: Geoliner or Protractor, Power Pack Light Kit & accessories, White paper Method: Analysis Angle of Incidence Refracted Angle 5 4 0 6 5 8.5 20 0 25 3 30 6 35 9 40 22 45 26 50 27.5 55 29.5 60 33.5 65 35.5 70 36.5 75 37 80 37.5 85 38 It can be seen that from the table, the light ray is bent towards the normal because the angle of incidence is greater than the refracted angle thus stating that the Perspex block is of a greater density than air. The graph above shows the angle used against the refracted angle. From the graph it can be seen that as the angle used increases the refractive angle is also increased. Sin I Sin
Investigate how the speed of light differs in air and in Perspex.
Gcse Physics coursework: Refractive Index Planning Aim: I am going to investigate how the speed of light differs in air and in Perspex. Background info: The refractive index is a ratio for working out the speed of light. The ratio varies for different substances, it indicates the extent to how light refracts through different substances. On passing from a less dense medium to a more dense medium, light is refracted towards the normal, and thus the angle of incidence, i, is larger than the angle of refraction, r., Willebrord van Roijen Snell (1591-1626), came up with a law explaining the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for any given pair of medium. so a simple statement of his law is: sin i / sin r = a constant, n So in this equation the constant n is equal to the refractive index. N defines the speed of light in Perspex as a decimal of the speed of light in air Example of refractive index values are: water (1.33); perspex (1.49); window glass (1.51); different glasses (between 1.46 and 1.69); and diamond (2.42). Diamond has a very high refractive index this is responsible for it having such a aparkle. Apparatus Lab pack D-block Ray Box Glass lens Collimator Prediction I Predict that the speed of light in Perspex multiplied by the refractive index of Perspex (1.49) will equal the speed of light
An Experiment to investigate the change of speed of light through perspex.
An Experiment to investigate the change of speed of light through perspex Aim To measure the change of speed of light in perspex and the in the air and record the lateral displacement of the ray. Background Information Light is an electromagnetic wave. The speed of light depends on the medium through which it propagates: it goes fastest in vacuum, almost as fast in air but considerably slower in glass. The speed of light in vacuum has been given its own symbol: c. The speed of light in any other material is denoted with v. The ratio of the two is known as the refractive index with the symbol n. When light goes from one medium to another, it doesn't only change its speed. Part of the incident light is reflected, and the remainder is transmitted. The transmitted light is generally also deviated or refracted. It was found experimentally by Descartes and by Snell, some 400 years ago that: • The incident, reflected and refracted ray all lie in the same plane • The angles of incidence ? a and refraction ? b and the refractive indices na and nb of the media are related through what has become known as Snell's Law: Equation na Sin ? a = nb Sin ? b Prediction My first prediction is that the angle of incidence will be 2/3 of the angle of refraction. This is because sin I divided sin r is the refractive index, which should be 0.66. Also to back up my prediction I did a
Wave Motion and Definitions
"A" Level Physics. Wave Motion and Definitions 2.2 2.2.1 What is a wave ? Waves involve a disturbance from an equilibrium position and the propogation of that disturbance from one region of space to another. Eg a brick thrown into a pond. (1) Pond showing water in equilibrium position. (2) Pond showing a disturbance from an equilibrium position. (ie brick thrown into pond) (3) Disturbance is propogated. 2.2.2 Wave Definitions Progressive Wave is one that carries energy and momentum from one place to another, without there being a transfer of matter (ie the material that the wave is moving through eg the water in a water wave). Stationnary Wave is the superposition of two waves of equal wavelength travelling towards each other at the same speed. Unlike progressive waves there is no net transfer of momentum or energy by the wave (see later for details about superposition). Mechanical Wave is one in which the wave is carried by material substance eg water for water waves, air for sound waves or vibrating string or slinky ! Electromagnetic Waves may travel through a vacuum and require no medium eg waves all the waves in the electromagnetic spectrum. The waves are caused by vibrations of electric and magnetic fields. 2.2.3 Wave Nomenclature * Period T * Frequency f * amplitude A * displacement x * wavelength
The aim of this experiment is to investigate the relationship between the length of a closed tube and the frequency of the lowest fundamental note.
Length and frequency of a fundamental note Aim: The aim of this experiment is to investigate the relationship between the length of a closed tube and the frequency of the lowest fundamental note. Plan: Clamp and clamp stand Speaker Ruler Hollow tube (diameter 0.025m) Signal generator Measuring cylinder Water The experiment will be setup as shown in fig 1. Method: The Hollow tube is suspended by the clamp stand in the measuring cylinder which is filled with water. This effectively seals it off creating a closed ended tube that can have the length adjusted by moving the tube up and down in the water. The length of the tube is then measured from the top to the waterline. The speaker is connected to the signal generator and is suspended above the tube. The signal generator will go through frequencies from 200Hz to 560Hz at 40Hz intervals (this was previously decided, the evenly spaced samples will make finding a relationship easier). At every frequency the tube will be moved up or down until it is in the position that creates the lowest loud noise possible (without changing anything else). This is the fundamental note, the lowest and loudest note possible at a certain frequency. It is produced by a standing wave being setup in the tube, these occur when the outgoing wave, and the wave that is returning from the end of the tube mirror each other and for this to happen
Do mobile phones adversly affect our health? - Case study
-------------Contents----------------------------------------------------------------------------- Pg.2 ------------------------------------ Introduction, Scientific Theory Pg.3 ------------------------------------ Mobile Phones Are/Aren't Dangerous Pg.4 ------------------------------------ Comparison, Conclusion, Bibliography Pg.5 ------------------------------------ Bibliography continued -------------Introduction------------------------------------------------------------------------ I am doing a case study for physics with the hypothesis "Using a mobile phone affects our health negatively". I have begun by looking at different websites for the facts. For example The Times article says that "The number of mobiles in Britain has doubled to 50 million since the first government-sponsored report in 2000" and the International Communications Union tells us that "About half of the world's population has a mobile phone today with mobile phone ownership worldwide topping 3.3 billion at the end of 2007". This is confirmed below. These are just a few figures that explain how serious this hypothesis is. If it does affect your health negatively, then 3.3 billion people could be at risk. I have also stated my own opinion in a conclusion and Amount of Mobile Phones worldwide - Source: IC Insights -------------Scientific
Compare the measured refractive index of three liquids against the unknown values and to then use the technique to measure the refractive of an unknown liquid.
Compare the measured refractive index of three liquids against the unknown values and to then use the technique to measure the refractive of an unknown liquid. Diagram Pilot A pilot experiment was carried out, using a Perspex block. The block was placed onto a piece of paper and drawn around to ensure that the block remained in the same place throughout the entire duration of the experiment. The normal was also drawn and from this, five different angles of incidence were drawn. These were placed at 10,20,30,40 and 50. At each angle of incidence a ray of light was shone and the light that entered and exited the Perspex block was noted and the angle of refraction measured. Method Refraction is caused by the change in speed of light when it passes into a medium that has a different optical density to air or the medium through which it is passing. A Perspex tank will be placed on a piece of paper and drawn around. Then the shape will be cut out. The tank will then stay in this position. The tank will be filled around 2/3 full of liquid. A book will be placed either side of the tank and the piece of paper with the hole in will be placed over the top, the tank going through the hole. This will prevent the light ray from going through the small lump at the bottom of the tank. It also creates a new level. A ray box will be placed in a certain position so that the ray will go
Investigation Into How the Depth of Water Affects the Speed of a Wave
INVESTIGATION INTO HOW THE DEPTH OF WATER AFFECTS THE SPEED OF A WAVE Aim To find how the depth of water affects the speed of a wave. Waves are vibrations (or oscillations) moving through something - a medium. As a wave passes, each bit of the medium vibrates in turn. The vibrations appear to move through the medium. Each bit of the medium in turn vibrates/oscillates, but stays where it is. The wave transfers energy as it moves. The medium can be matter (solid, liquid, gas). This is the case for water waves. There are two types of wave: a) Transverse waves. The vibrations are at right angles to the direction of the wave. b) Longitudinal waves. The vibrations are along the same direction as the waves. The waves I will be studying are transverse waves. During a previous experiment I found that a drop height of 5cms and to allow the wave to do 3 laps of the container before stopping the stopwatch was the best course of action. 5cms is a good height because it is high enough to cause a strong wave, but not high enough to create water to spill over the container's edge. I chose 3 laps because after that the wave starts to lose momentum and slows down. Apparatus Container Stopwatch Ruler Water Prediction I predict that the greater the depth of water, the faster the waves will travel. The reason for this is that when the water is shallow,
IB Physics Practical - Stubbiephone Wind Band
Physics IB Physics Practical Assessment Skill 1: Planning (Part A and Part B) Stubbiephone Wind Band The music department of a school is in need of an instrument that covers a range of one octave (eight notes). Such an instrument, however, cannot be purchased due to the shrinking budget of the department and a hand made alternative needs to be produced. It has been decided that the instrument will be made up of eight short and fat beer bottles because beer bottles are cheap and readily available. This report contains a plan for an experiment to investigate how these bottles can be made to produce the eight notes required to form an octave. PART ONE - PREDICTION The shape of a beer bottle can be compared to that of a closed pipe, with one end of the bottle open, the mouth, and the other end closed. When we blow over the mouth of a beer bottle, a sound is produced. It is known that sound travels through a closed pipe in the form of a standing wave, with the node at the closed end (bottom of the bottle) and the anti node near the opening of the bottle as in figure one(a). The length of the standing wave in a bottle is equivalent to the actual length of the bottle. Therefore, to vary the length of the standing wave will require the length of the bottle to be changed. One way to do this is to fill the bottle with water. Referring to figure one(b), we can see that when a
