Soil water content in relation to species diversity in a Pingoe.
Soil Water Content in Relation to Species Diversity in a Pingoe Introduction Fouldon common is situated in the east of England near Norfolk. The area has been classified a Site of Special Scientific Interest as it is a rare habitat known as Ancient Chalk grassland. It is because of the large amounts of chalk in the ground that the soil is alkaline and has a PH of around 8.0. There are very few areas of natural grassland present to day as most are used for agricultural purposes or have developed in to woodland. There are two main reasons why this is not the case at Fouldon common, the first is the presence of pingos and the second is grazing. In past years the people who lived in Fouldon had gazing rights this means that they were able to use the land for grazing there own animals such as sheep. Due to agricultural advances there has been a decline in this from the beginning of the twentieth centaury. The other main source of grazing at Fouldon common was from Rabbits. Unfortunately due to the Myxomatosis epidemic in the 1950's the population of rabbits at Fouldon common like many other places across the British Isle has declined. This then resulted in a serious drop in the amount of grazing at Fouldon causing large amounts of the grassland to develop into scrubland. Now under new ownership precautions to insure the preservation of the common have been put in place, this
Effect of Underwater Acoustics on Whales.
Effect of Underwater Acoustics on Whales Biology 220W Leah Kim Student ID # 207740335 Section# 001 Abstract: Whales utilize acoustic frequencies to communicate underwater. If the whales are unable to communicate their bi-annual migration can become perilous. Man-made low frequency sonar can prevent whales from producing sound and sometimes causes them to take alternate routes. When the whales try to avoid the sonar they are in danger of running ashore and perishing after being beached. Introduction: Twice a year, around the months of December and May, populations of gray whales migrate from Mexico to Alaska. (Unknown1, 2002) During this journey, they pass the state of California, where acoustical pulses, generated by air guns or water guns, are used in seismic surveys. If the seismic-generated sound waves exceed the "background" noise or normal amount of noise, they could interfere with gray whale communication or disturb behavior. (Unknown1, 2002) It is possible that seismic surveys have a detrimental impact on marine life, such as gray whales. Whales are able to perceive sound in a wide range of frequencies from 75 Hz up to 150 Hz. In experimental conditions, where the environment's level of noise is controlled, the whales are more sensitive and hear from 10 Hz to 100 Hz. In addition, smaller whales have a broader range from which they can hear from 10 up
An Investigation into the Effect on the Critical Angle by Changing the Colour of Light
An Investigation into the Effect on the Critical Angle by Changing the Colour of Light Aim: To investigate the factors affecting the size of the critical angle through a median of Perspex Background Information: The critical angle of light is when it hits a different median from the one it had been travelling in, for example glass to air at a certain angle that causes total internal reflection. This angle is different for all lights and medians. Total internal reflection is when a beam of light travelling through a certain median is reflected back at an angle that is equal to its incidence instead of just being refracted and then passing out the other side. This phenomenon is used to transmit information through fibre optic cables. Fibre Optic cables have a beam of light sent down them in which the information is encoded. The beam of light is angled to hit the side of the cable at an angle greater than medians critical angle (42°). The beam then reflects off one side of the cable then to the opposite side. Again the angle of incidence is greater than the critical angle. This is then repeated all the way to the end of the cable where the information is needed. Practical applications include digital audio transmitters which allow CD quality sound to be sent from one place to the other, with hardly any loss of quality. Other applications include Cats Eyes which are
Physics Essay: Making Music
Michelle Clarke 12MA October 2001 Physics Essay: Making Music Music is made from a number of sound waves being combined together. These sound waves are produced by the source instrument and can be changed, by adjusting the frequency or speed of the wave. Wave motion can be simply described as a mechanism by which energy is conveyed from one place to another in mechanically propagated waves without the transference of matter. The oscillation may be of air molecules, as in the case of sound travelling through the atmosphere; of water molecules, as in waves occurring on the surface of the ocean; or of portions of a rope or a wire spring. Waves are changes in pressure of the air; sudden changes in the pressure create sounds. In the case of producing sounds the waves usually travel through the air, as a longitudinal wave. This longitudinal wave is caused by vibrations, which alternately compress, then decompress the particles in the medium (e.g. air or water) through which the wave is travelling. These vibrating particles transfer energy. This diagram shows how the sound waves travel through its medium. (Sound always requires this medium so that the particles can vibrate, and carry the wave. Therefore sound cannot travel through a vacuum.) As sound is a wave it follows the many rules of waves, these include the importance of frequency and wavelength. As in all waves, the wave
During this coursework practical, we aim to study the behaviour of water waves at various depths of water.
GCSE PHYSICS COURSEWORK . PLANNING AIM During this coursework practical, we aim to study the behaviour of water waves at various depths of water. METHOD Firstly, a plastic tank is obtained and its length is measured and recorded. 0.5cm depth of water is poured into it; this depth is measured using a wooden metre rule, vertically positioned resting on the bottom of the tank. One end of the tank is lifted up and is then dropped. This causes a ripple (wave) of water travelling across the water surface to be seen. The time taken for the ripple to get from one end of the tank to the other is timed using an electronic stopwatch (i.e. from one 'bounce' to the next). This is repeated twice more for the 0.5cm depth of water. Then the whole process is repeated with different depths: 1.0cm, 2.0cm, 2.5cm, 3.0cm and 4.0cm, again all tested thrice each. Averages of the results collected are taken to level out any anomalies, the results are analysed to investigate the behaviour of water waves at various depths of water, and the speed is calculated for each water depth (speed = distance ÷ time). DIAGRAM PRELIMINARY WORK Before the real coursework experiment, some preliminary investigations were conducted. We experimented with the tank being filled with just one particular water depth, to try to work out if the wave (ripple) we caused would travel at a steady speed or not (using a
Investigation of the response of a microphone / loudspeaker over a range of frequencies
Investigation of the response of a microphone/loudspeaker over a range of frequencies Aim & Hypothesis To become proficient with using a signal generator and a Cathode Ray Oscilloscope (CRO.) Also, to investigate how the amplitude of a signal from a microphone varies as the frequency of a fixed amplitude signal applied to the loudspeaker varies, (between 100Hz and 1000Hz.) Safety RISK ASSESSMENT - LEVEL ONE This experiment does not carry many hazards. Bags and coats will be moved out of the way to ensure that no one will trip over them. The only other potential danger is as a result of using mains operated equipment. I will not be using the equipment near any water, taps etc. I will do a visual check on the equipment before use (not fraying or lose wires, etc.) Variables Independent Variable: Frequency (Hz) Dependent Variable: Amplitude (mV) I will be using the signal generator to alter the frequency being produced - therefore this will be the independent variable. This will alter the amplitude of the wave being shown on the CRO so this is the independent variable. I have used the same equipment throughout the experiment in order to ensure a fair test. Diagram Method The apparatus was set up as shown on the previous page. Firstly I did three 'checks' to ensure that (to check if they are properly calibrated.): * The amplitude of the signal remains constant *
Investigate how the angle of refraction is affected by different inputs of the angle of incidence through a glass block.
Physics Investigation I am going to investigate how the angle of refraction is affected by different inputs of the angle of incidence through a glass block. Background Information: When light goes from air to another transport material it slows down - only slightly, but enough to make it change direction or refract. Refraction can be explained using wave theory. As the light waves hit the boundary with the second material, they slow down. This causes a change of direction towards the "normal" as the light waves are "bunched up" (a shorter wavelength). When light passes back out into air, the refraction is away from the normal, because the light speeds up. Rays of light travelling from air into glass are bent or refracted towards the normal. Rays of light travelling from glass into air are refracted away from the normal. In other words the angle of refraction is less than the angle of incidence. When light leaves a transparent material, it bends away from the normal. Snell's law The law of refraction relates the angle of incidence (angle between the incident ray and the normal) to the angle of refraction (angle between the refracted ray and the normal). This law, credited to Willebrord Snell, states that the ratio of the sine of the angle of incidence, i, to the sine of the angle of refraction, r, is equal to the ratio of the speed of light in the original medium, vi ,
Optics - the human eye and coomon defects
Eye Defects Vision:- The mammalian eye could be regarded as a miracle of evolution. In order to produce an image the eye has to act as an Optical refracting System (to focus a sharp image) and a Photo Detector (to analyse the image and send information to the brain). At the front of the eye is the optical system, made up of the transparent curved Cornea and the adjustable biconvex Lens. The photo detector is the layer of light-sensitive cells at the back of the eye, called the Retina. The amount of light entering the eye is controlled by the Iris. Sharp focusing is achieved by altering the shape of the lens. The shape of the lens is controlled by the ring of ciliary muscle which runs round the outside of the lens. (http://www.riverdeep.net/current/2002/01/012002_images/eye.jpg) Defects in the eye:- . Long Sight (Hypermetropia) In this condition we can see distant objects more clearly that ones that are nearby. This is usually because the cornea is not curved enough, which reduces the angle of refraction, and the lens cannot accommodate sufficiently to bring the diverging rays from near objects into sharp focus on the retina. 2. Short Sight (Myopia) In this condition near objects are clearly seen, but distant objects cannot be brought into the focus. It happens when the cornea is too curved; the light from distant objects is refracted too much and comes to a focus in
Graphs illustrating variants of y = sin x.
Part 1 Graph 1 Graph 1 is showing y = sin x. Now lets look at the graphs of y = 2sin x ; y = ? sin x ; y = 5sin x y =2sin x Graph 2 y = 1/3sin x Graph 3 y = 5sin x Graph 4 If we compare graphs 2, 3 and 4 we can see that the number in front of sin (this number is called A) changes the vertical compression of the wave. When A<1 then the graph vertically compresses or amplitude becomes lower (graph 3) and when A>1 then graph expands vertically or amplitude becomes higher (graphs 2 and 4). If the number is 2, then the wave doubles vertically and when the number is 1/2 it compress by half. The comparison is of course made with the graph of sin x. Now let us see what happens when we make the equation negative by putting a minus sign in front of sin. By doing this we are taking A<0. Graph 5 Graph 5 shows us that the wave flips around when A is negative. So we can conclude that when A<0 the wave will always be upside down From investigating graphs of y = Asin x, we can conclude that when the A is less than 1 then the wave compresses vertically and when A is greater than 1 the wave expands vertically. If A is less than 0, then the whole wave flips upside down. To conclude we can say that A will equal to the number on the y-axis because
To investigate how the strength of an electromagnet change as you varies the number of turns of the coils.
Physic coursework on electromagnet Aim: To investigate how the strength of an electromagnet change as you varies the number of turns of the coils. Introduction: In this experiment, we are going to design a circuit to test what factors can make the electromagnet stronger and how we can do that. Electromagnet is a solenoid (coil of wires) with an Iron core. When an electric current flowing through a wire, it creates a magnetic field in the region of the wire. This is a way how magnetic created, which is known as electromagnetism. Solenoid is a long coil made up of a number of turns of wire. When a current flows through solenoid each turn acts as a single coil and produces a magnetic field. This diagram shows the field pattern around the solenoid. There are some methods to increase the strength of the electromagnet, which are: - . Increase the size of the current. 2. Increase the number of turns the coil has. 3. Use a soft iron. Using a soft iron can increase the strength of the electromagnet, because it can turn off and on, therefore it can change easily between being magnetized and demagnetized. The reason why increasing the number of turns of the coil will make the electromagnet stronger, because the size of the magnetic field produce by the coils will increase. There are many advantages of using an electromagnet in many places. For example: In many electrical
