Find a relationship between the angles of incidence and the angles of refraction by obtaining a set of readings for the angles of incidence and refraction as a light ray passes from air into perspex.
Refraction of Light Aim: To find a relationship between the angles of incidence and the angles of refraction by obtaining a set of readings for the angles of incidence and refraction as a light ray passes from air into perspex. Introduction: Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law. (Refer to diagram below) The index of refraction is defined as the speed of light in vacuum divided by the speed of light in the medium. In this experiment, the index of refraction for the perspex is 1.50. Snell's Law relates the indices of refraction of the two media to the directions of propagation in terms of the angles to the normal. It refers to the relationship between the different angles of light as it passes from one transparent medium to another. When light passes from one transparent medium to another, it bends according to Snell's law which states: where: n1 is the refractive index of the medium the light is leaving, n2 is the refractive index of the medium the light is entering, sin 2 is the is the incident angle between the light ray and the normal to
The Electromagnetic Spectrum.
Electromagnetic Spectrum The Electromagnetic Spectrum is a range of all the electromagnetic waves, these range from radio waves with the lowest frequency and the biggest wavelength to gamma rays with the highest frequency and the smallest wavelength. The main eight categories of electromagnetic waves are: . Radio Waves 5.Ultraviolet 2. Microwave through far infrared 6.X - Rays 3. Near infrared 7.Gamma Rays 4. Visible 8.High Energy Gamma Rays Most of these categories split into smaller subdivisions, for example visible waves split into different visible coloured waves. Radio Waves Radio Waves are a type of electromagnetic wave and like all others travel at the speed of light. They occur naturally in our environment by lightning or some astronomical objects, we produce them with our mobile phones, radios, GPSs and many other electronic devices. Microwaves Microwaves have frequencies between 1010 and 1011 Hz, and have a wavelength of 10-2 to 10-3 , they are produced by microwaves, ovens and microwave transmitters and are detected by microwave receivers. We use them in cooking foods, communication and radar so when you use a microwave you're using microwaves or when you're using a mobile phone you're using microwaves. Infrared Infrared covers waves with wavelengths between 1mm to 50 nm and frequencies from 300GHz to 400 THz; however it can be
Is there any rule governing the angle light is refracted through?
Is there any rule governing the angle light is refracted through? Aim: To find a connection or rule governing that angle light is refracted through. Introduction: Visible light is s form of energy that we can detect with our eyes. Light moves in waves. The light that we can see has a wavelength of about 1/2000 of a millimetre. The speed of light in air is 300 million metres per second. This is about a million times faster than the speed of sound. Light travels more slowly in glass than it does in air. It goes about two-thirds as fast through glass than it does in air. This is the reason why light is refracted. Since the light is being slowed down by the optically more dense medium, the ray of light travelling from the air into the glass will bend towards the normal. As below: A number called the refractive index measures how quickly light travels through a certain material. To work this out you would need this following equation: Refractive Index of a substance = Speed of light in air Speed of light in the substance The refractive index of glass and Perspex is 1.5. The greater the number, the slower light passes through the substance. Here are some other refractive indexes for other materials: Substance Refractive Index Speed of light Air 1.0 300,000,000 Water 1.33 225,000,000 Perspex 1.5 200,000,000 Glass 1.5 200,000,000
The aim of my experiment is to see what factors affect electromagnetism the most so as to give the best electromagnet in an experiment.
Nicholas Marshall 10A Monday 1st July 2002 Physics Coursework- Electromagnetism Aim- The aim of my experiment is to see what factors affect electromagnetism the most so as to give the best electromagnet in an experiment. The factors I will use are: the number of coil wraps around the iron nail and the amount of current in the circuit. It is these factors that I will use to see which one gives the best electromagnet. Scientific Knowledge- How to get an electromagnet- When an electric current flows through a coil of wire it sets up a magnetic influence or 'field' around the wire. The more turns of wire there are in the coil and the bigger the current, the stronger this magnetic field will be. An easy way to wind the wire is around an object and a winding like this is called a solenoid; if now an iron core is put through the hole in the coil it will become an electromagnet when a current is sent through the wire around it. The reason for using iron is that it concentrates and strengthens the magnetic field. An Electromagnet in Electron Terms- This part is quite simple. A current is made up of electrons, so when you say a current flows you could also say when electrons flow. So if a current creates a magnetic field then the electrons also create a magnetic field. So the flow of electrons gives a magnetic field, which in turn creates the electromagnet. So the
What factors affect the strength of electromagnetism?
Physics Coursework What factors affect the strength of electromagnetism? Planning Introduction A home made magnet is essentially a metal core, with a wire coiled around it. The core should be a 'soft' metal, for example soft iron. A 'soft' metal is one that is easily magnetised and demagnetised, and a 'soft' iron core increases the field strength. A wire coil that carries current is called a solenoid, and this solenoid is wound around the soft iron core. When a current is passed through the circuit, and the coil, a magnetic field is produced at the centre. This aligns the particles in the iron core, which are tiny magnetic domains pointing in all directions in the absence of current, in one direction. A magnetic field is produced around the electromagnet - a magnetic field is a region where magnetic materials (e.g. iron and steel) and also wires carrying a current experience a force acting on them. Magnetism is said to be induced in the soft iron core, that is, the soft iron core becomes magnetised. It is electricity through the coil and the magnetism that it induces in the iron core, which give it the name electromagnet. I used the book "Physics for You" by Keith Johnson. De-magnetised metal Magnetised Metal Factors There are numerous factors but I will talk about the three main factors. * The number of turns on the coil * The current through the coil * Material
Physics investigation- Strength of Electromagnet
Physic investigation- Strength of Electromagnet Aim The aim of the investigation is to find the strength of an electromagnet and how this is affected by an increase in current (I). We already know that other factors that increase the strength are the amount of coils and the inclusion of an iron core. Factors We will control the current using a variable resistor and measure it using an ammeter; we will keep the voltage the same. Keep the distance of the electromagnet from the scales the same. Make sure the magnet that is upon the scales is always in the same position. Also keep the distance of the last coil from the end of the iron core constant. We will have to keep the amount of coils around the iron core the same throughout the experiment and not add or take away an iron core. Hypothesis As the current increases the strength of the magnet increases. This will appear as a proportional line on the graph, but eventually the line will level off and the strength of the magnet will become saturated and the magnet will have found its maximum strength. Why? 'Stephen Pople's co-ordinated science' book supports my hypothesis on pages 152-153, here it mentions that an electromagnet can become saturated after so many coils have been wrap around the iron core. It tells us that an unmagnitised piece of iron has its domains spread out and angled in different directions When you
Investigating the factors which affect the sideways displacement of a light ray through a glass block.
Physics Coursework: Investigating the factors which affect the sideways displacement of a light ray through a glass block Plan: Refraction: Refraction occurs when light travels from one medium to another in which the speed of light is different. The speed in glass is slower than its speed in air so light is refracted when it travels for air to glass, or vice versa. This change in speed usually results in a change in the direction in which light travels. Aim: I'm going to investigate the factors, which affect the path of a light ray through a glass block. These factors are: * Angle of incidence * Material * Thickness of material The factor I have chosen is the angle of incidence because it is the easiest to carry out in the classroom since it would be difficult to find different materials that could be tested. Also it would be difficult to find one material with different thickness (to overcome that more than one of the materials could be put together however it would not be completely accurate since there will be a small gap between the two or more pieces. The experiment I am going to carry out is an experiment to show the sideways displacement of a light ray through a Glass Block. Apparatus: )Glass block (60 mm wide) 2)Ray Box (with as narrow ray as possible for more precision in measuring the angles) 3)Protractor (with a small scale
Mobile Phone case study
Gary Thompson Monday 30th March 2009 Science Case Study: Do Mobile phones affect our health? - Page 3 - Page 4/5 - Page 6 - Page 7 - Page 7 - Page 8 Introduction My coursework piece for physics had to be based on the topic of the effects of radiation emitted from mobile phones. Therefore, I began my case study by researching people's opinions on the subject. In this case study, I plan to investigate both the arguments for and against my question: "Does use of mobile phones adversely affect our health?" I will do this by using a number of sources and by researching evidence that back up my own ideas. In addition to this, I will conclude this case study with a final look at my opinion. Scientific Theory Mobile phones work using cells. That is where the American term "cell phone" derives from. Each cell has a base station as its centre. The base station sends and receives calls from the phone. There are three different types of base station; Macrocells, Microcells and Picocells. Macrocells are the largest type of base stations and provide the main coverage for mobile phone networks. Its antennas can be mounted on ground-based masts, rooftops or other structures and must be high enough to avoid obstruction. Macrocells provide radio coverage over different distances, depending on the frequency used, the number of calls being made and the surrounding environment.
Measuring the speed of light
Measuring the speed of light The first real attempt at measuring the speed of light was made by Ole Christensen Rømer in 1676. He was studying Jupiter's moon Lo motions with a telescope. He observed that Io went round Jupiter once every 42,5 hour when Earth was at it's closest to Jupiter. When Earth moved away from Jupiter Los its motions took slower than Rømer predicted. The signals from Lo took longer to reach Earth when Jupiter moved away from Earth. The signals from took longer to reach earth when the two planets moved away from each other. This was because of the extra time it took for the light to cross the extra distance. He calculated that it would take about 22 minutes to cross the diameter of Earths orbit. Using these calculations Rømer found the speed of light. He measured the distance between the sun and Earth and found out that the speed of light was 125,000 miles per second. James Bradley (1728) was not satisfied, he said that starlight could cause an "aberration of light" and could cause speed of light measurements go wrong. Rømer used an Astronomical method. Hippolyte Fizeau in 1849 used an earthbound method to measure the speed of light. He used a beam of light reflected from a mirror 8 km away. The beam was passed through the gaps between the teeth of a rapidly rotating wheel. The speed of the wheel was increased until the beam of light passed
Experiment to investigate the relationship between speed and depth for a water wave.
Physics Coursework Aim: Experiment to investigate the relationship between speed and depth for a water wave. I predict that the greater the depth of water the faster a water wave would travel. Speed=distance travelled / time Prediction: As I explained earlier, the greater the depth of water the faster a water wave would travel. The angle of the guttering is a major factor in this as changing the angle would make the guttering unlevel and will slow down the wave therefore making the experiment unfair. Apparatus: The equipment I need to carry out the work and to obtain my results is: · A length of gutter · Water · 250cm3 Beaker · Metre Ruler · 30cm ruler · Retort stand · Clamp · String · A wooden block · Stopwatch Diagram: Preliminary Work: Preliminary work is the work that is done beforehand for you to know that the experiment is going to work. It is a way for the person carrying out the experiment to know that it has been set up correctly when the actual experiment begins. For my preliminary work, I did the experiment and tested that a wave would be able to be created. The preliminary work brought up the problem of how high the wooden block should be held up before it is swung into the water, it was decided that it should be swung from about 4cm above the bottom of the guttering. Safety Precautions: Even though safety is a virtue the
