Universe - Definitions
Quasars Possibly extremely dense neutron stars giving off radiation. Once thought to be the bright centre of other galaxies. Pulsars These are neutron stars that emit an enourmous amount of radiation. They spin hundreds of times a second and we pick up the radio waves on Earth. Neutron Stars Formed from very large stars collapsing. Between 10 and 100 km in diameter a they can have a mass many times that of the sun. A star 8 times that of the sun creates a neutron star 1.5 times that of the sun. The rest of the mass is blown into the space. Black Holes Black holes that are worth considering are only found at the centre of galaxies. The centre of every galaxy has a black hole. It keeps the galaxy together with its immense gravity and is 10 times denser than what would be expected if there were just stars at the centre of our galaxy. Nothing escapes, not even light. Photons are captured and added to the gravity. 0 point field No dimensions. Cells take light from it to tell other cells where to go in growing. Where does gravity come from? There is infinite energy from gravity so in theory it could be converted into infinite
The Electromagnetic Spectrum.
A2 Physics Coursework Almost all the information about the known universe comes from different types of waves. Most of what we could originally see was made up of visible light. Visible light is made up of Blue, Green and Red light. Each colour has a different wavelength and when combined for a white light. What we can see (visible light has a wavelength of between 400 to 700 nm) only represents a very small proportion of the light spectrum (known as the electromagnetic spectrum). There are many other forms of electromagnetic waves we can't see. Radio waves have wavelengths billions of time longer than those of visible light. They are used to transmit radio and television signals and can range from less than a centimeter to hundreds of meters. Inferred again has a longer wavelength than visible light however shorter the radio waves. Although invisible to the naked eye we can often feel them in the form of heat. Ultra violet is shorter than visual light ranging from having a wavelength of 400nm to 10 nm. The shorter a wavelength is the higher amount of energy it contains. This is why UV light from the sun can damage your skin. X-rays are also very high-energy waves and can be dangerous when exposed to them for long periods of time. Gamma waves are less than 10 trillionths of a meter and are even more penetrating then X-rays. The electromagnetic spectrum is not only measure
We are aiming to investigate the effect of force upon a spring. We will also investigate Hooke's law, to see what happens using two springs in parallel and series, and how this effects the spring constant.
Investigation - Hooke's Law Aim: We are aiming to investigate the effect of force upon a spring. We will also investigate Hooke's law, to see what happens using two springs in parallel and series, and how this effects the spring constant. Background: I know that Hooke's law states that spring extension is proportional to stretching force, so long as the spring was not permanently stretched. In this investigation we will explore this statement. Trial Run: We did a trial run before starting the main experiment, and we found that we had to carefully put the weights on to the hanger, as the spring quickly stretches and could break. We also had to make sure we took the measurements at the same place each time, i.e. at the bottom of the spring or the bottom of the hanger, as this could affect our results. We also found that the spring could take 10N without deforming. Prediction: From the scientific knowledge above I can make a prediction about this experiment. I predict that the extension of the spring will be proportional to the force applied to it, and that it will return to its original size when the force is released. When we have two springs in parallel I predict the force will have an effect on them as a whole, and they won't stretch as much as the single spring, so the spring constant will increase. When two springs are in series I predict the force will have
How the angle of a solar cell affects its output.
How the angle of a solar cell affects its output Introduction: The aim of the experiment is to investigate the relationship between the angles of a solar cell from its light source to the output of the solar cell. I will be able to see how the relationship changes (if there is a change) by the results which I record. Apparatus: The equipment which I will require to carry out my experiment are: A solar cell A multimeter A light source These are the things which I will need to carry out the experiment but I will also need equipment make sure the experiment is accurate, these are: A clamp side with clamp, a piece of wood and blue tack, this will act as a stand on which my solar cell will be placed. The clamp stand and clamp will hold the piece of flat wood in a fixed position, to which the solar cell will be blue tacked into position, this will keep the cell firm and steady. A ruler will also be used to measure the distance of the solar cell from the light source. And a protractor will be used to measure the angle at which the solar cell is placed Diagram Safety In order to carry out this experiment in a safe way I will have to consider a few safety issues. I will have to be careful while working around the light. Because once the light has been switched on and left of a period of time the filament within the light bulb will start to heat up (because of the
Experiment to measure deflection when a force is applied to a cantilever.
Sc1 Investigation - bending of a Cantilever. Experiment to measure deflection when a force is applied to a cantilever. Introductory Diagram Aim To find out whether varying the load has any affect on the deflection (?d) of the ruler. Theory Elasticity is the property, which allows a material to regain its shape after being distorted. Some materials like, rubber bands, are much more elastic than others. The elastic limit of a material is the maximum amount by which it can be stretched and still regain its original shape after the distorting forces are removed. If a material is stretched beyond its elastic limit its shape is permanently changed. ' The deformation of a material is proportional to the force is applied to it, provided the elastic limit is not exceeded'. This is known as Hooke's Law, named after its discoverer, Robert Hooke, a 17th century scientist. Young's Modulus When stress is applied to a material, strain is produced in the material. The strain is proportional to the stress, provided the stress does not exceed a limit known simply as the 'limit of proportionality'. Within this limit, the value of is a constant for that material, and is known as the Young Modulus for the material. The Young Modulus (E) = Provided the limit of proportionality is not exceeded. Before we can work out the Young Modulus we need to know about stress and strain.
Stretching Springs/Hookes Law.
Mustafa Rafik 0.7Api Science coursework Title: Stretching Springs/Hookes Law Mr Bhatwadekar Scientific knowledge A force is able to change the shape of an object, the more the strength and force you apply, the more the shape of the object will change because the particles of the object are being moved therefore it will change the shape of the object because of the particles being pushed for e.g. A force is also able to change the motion of the object. The force, which is applied to the object, makes the object stay in that shape which is the cause of the force hitting the object and making it change, this will not go back to its original shape like shown in number 2, this is because the particles have been hit so hard that the attraction of the particles which makes them go back to its original shape have been damaged so it will then go into another shape. Elastic material This is a material that will stretch and go back to normal, its original shape. Elastics behavior is the ability of a solid to regain its shape when the external forces are removed. What is Hookes Law? Hokes Law is a rule for a spring, 'For a spring-that for a helical spring or other elastic material the extension is directly proportional to the applied force provided the elastic limit is not exceeded' This means that the extension is directly proportional to its force until its elastic
Investigation based on Hooke's law.
Background Information. This investigation will be based on Hooke's law. Robert Hooke was born in 1635, he was well known for his studies of elasticity. Hooke's most important discovery is the correct formulation of the theory of elasticity. An object is said to behave elastically when equal increases in the force applied to it produce equal changes in length. If a graph is drawn to show the average extension plotted against the load in Newtons a positive straight-line gradient should be seen, as extension is directly proportional to the load. The ratio between the load and the extension gives us a constant, this constant is called the spring or force constant. Hooke's law states: F = kx k = the constant of proportionality (the spring constant). x = the spring extension (e.g. x metres) Or: The deformation of a material is proportional to the force applied to it provided the elastic limit is not exceeded. The elastic limit is when the spring is permanently stretched on deformed, so it doesn't return to its original shape, as the molecules in the metal of the spring cannot return to the original shape; as the following graph demonstrates. Elasticity can also be shown in this simple diagram: The Molecular Level Description. Before. After. Combinations of springs. Hypothesis. ) I think that the stretch of the two springs in series will be double the stretch of
What is the speed of sound waves?
What is the speed of sound waves? Prediction: I predict that the speed of sound in air will be 330m/s. Method: The apparatus were sat up as below. The metal plate was held 10cm above the start microphone. It was then hit with the hammer and the time it took for the sound to travel to the stop microphone was recorded by the fast timer in microseconds. This was done twice and then the start microphone was moved to the 90cm mark on the ruler the process was repeated until the microphones were 10cm apart. However, nothing else was changed except the distance between each microphone. Result Distance between the microphones (metres) Time for Sound to travel from M1 to M2 (microseconds) 2 Average 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 3029 2996 2094 850 561 241 941 641 393 29 3023 2725 2181 2147 472 311 892 667 387 10 3026 2860.5 2137.5 998.5 516.5 276 916.5 654 390 19.5 Analysis The graph on the previous page shows the time that was recorded for certain distances. Those distances are different from the ones stated in the results table on page 1. However this will be explained later. If we look at the graph we can see how the points that were plotted lie very close to the line of best fit, with the exception of the last two circled points, and show a positive correlation. Also you can see how the line goes through the origin, which
What effects displacement of a ray of light?
Investigation: What effects displacement of a ray of light? Variables * The angle the light hits the block at * The width of the block * The colour of the light * Light intensity Predictions * The larger the angle the larger the displacement. (See Diagram) In the diagram I have used snell's law to find the refracted angle, Snell's law is that for glass Sin i Sin r = 1.5 By using this I have been able to work out accurate results without doing an experiment. * The displacement will be directly proportional to the width of the block. I.e. The wider the block the larger the displacement E.g. if you double the thickness of the block then the displacement will double (See Diagram) Plan 1 The apparatus that I need for the experiment is Protractor 2 Ray Box 3 Ruler 4 Blank page 5 Glass block 6 Power Pack The measurements to be taken are: the size of the blocks : The size of the displacement 5 readings will be taken; this is because a large range of results is required to draw an accurate graph. A ruler will be used to measure the displacement and thickness and a protractor will be used to measure the angle. The experiment will be repeated twice to give a range of measurements The test will be kept fair by making sure that the controlled variables are kept the same throughout all the experiments. The main controlled variables are: Colour of light-
Is Space Exploration Worth the Cost?
Is Space Exploration Worth the Cost? Abstract In this report I will investigate if space exploration is worth the cost of its budget. I will provide evidence for both side of argument and will include information about how satellites work. Finally I will come to a conclusion as to whether I think and space exploration is worth the cost and will evaluate all of the sources that I have used. Introduction Space exploration is the use of astronomy and space technology to explore outer space.The US spends $18.7 billion on space exploration every year, but the big question going through many minds is "Is it really worth the cost?" I will identify reasons for and against the spending of this money on space exploration and will include examples of perceived better uses for the designated budget. Reasons for Space Exploration Being Worth the Cost: Important new technologies which advance the economy are created through space exploration. For every dollar spent on the space program, the U.S. economy receives about $8 of economic benefit [1]. Some of these main advances in technology which shape our lives today include flat panel televisions, G.P.S, computer operations and mobile phones [2]. Space exploration has also provided technologies which save lives as well as entertain and convenient them. For example space exploration allows the prediction and management of hurricanes and