Lenses experiment plan Essays

Lenses experiment plan Essays Lenses experiment plan Essay Lenses experiment plan Essay Lenses are a transparent material shaped to refract light. Lenses are remarkable and have helped mankind develop in the so many years the world now uses for almost and visual activity from swimming goggles to open heart surgery lenses are used in some form. But lenses are not all the same. There are two main types of lenses convex and concave. These two lenses are opposites of each other and produce different images. Concave lenses are rarer to find in every day life. A concave lens is curved inwards it is shaped like two dishes placed back-to-back. Light passing through a concave lens diverges. Unlike convex lenses, which produce real images, concave lenses produce only virtual images. A virtual image is one from which light rays only appear to come from but in actual fact the do not. This appears as a smaller to produce image just in front of the actual object. Concave lenses are generally prescribed for short-sighted, people. Concave lenses help the eyes to produce a sharp image on the retina instead of in front of it. Convex lenses are more common in everyday life. The lens is very thick in the middle and thinner at the edges. With the unique shape of then lens it causes the lens to converge any light rays that pass through. This produces an image on any surface on the other side of the lens. The human eye lens is a convex lens and is more like an elastic lens and can change its shape to focus. When viewing objects at a distance the lens becomes short at and fat and when viewing objects close up visa versa. Aim: I will be using a ray box with concave and convex lenses to measure focal points. This will be done by sating up a ray box with a convex/concave lens and shining a ray beams through the lenses and drawing over the beams. With this experiment I hope to acquire the skill of measuring focal points and I will hopefully be able to use this skill later on in higher levels science. Safety There are many safety issues that arise when dealing with electricity and laboratorys that is why when conducting an experiment all safety aspects need to be thought about before carrying out the experiment otherwise someone could occur electrocution or a serious injury when conducting the experiment. Its a known fact that the human body can be damaged by electrical currents that is why it is important to take safety measures such as conduct the experiment away from water to prevent electrical fires. Before any experiments are started all the leads and wires should be checked for cuts and loos wiring exposed wiring etc. Another way of preventing electrical fires or electrocution is by checking that the equipment that is has a circuit breaker or a fuse with the rite amp. Another aspect of safety which needs to be considered is the breakage of glass. There are many safety issues that arise when dealing with glass. One of the main parts of the human body when carrying out experiments are they eyes do to the fact they can easily be damaged and are clearly one of the most delicate exposed parts of the human body. To protect these fragile biological sensors a form of protection is crucial. The most common form of eye protection in the laboratory are the goggles. The goggles appear to be very unattractive to many people but and are often interoperated as a burden and not a safety precaution. The goggles are made out of thick plastic which prevents any flying glass entering the eye and causing any harm to the eyes. Within the laboratory there are frequent breakages which can have damaging affects and can cause injury. That is why it is important to try and prevent breakages knowing what the effect of a breakage is and what to do about it. When these breakages occur they can be on minor scale or a disastrous scale. This depends whether the glass is shatters or breaks in to jagged pieces, most lab breakages are on a minor scale and can simply be swept up by using a brush. With hazardous breakages do not attempt to clear the breakage and find someone qualified to attend to the breakage. Method When the experiment was carried out the first thing that needed to be attended to was having all the correct equipment and materials at hand. The following equipment and materials were gathered: * Protractor- A semicircular instrument used for measuring and constructing angles. * Mirror- A surface that reflects light at the angle it hit the surface which creates a virtual image. * Convex lens- A lens which converges light. * Concave lens- A lens which diverges light. * Power pack- A power pack which controls the amount of energy that goes to the light box * Grates- To split the light in to equal and parallel rays. * Pencil- A rod of graphite cased in wood or metal used for drawing or writing which can be erased by an eraser. * A3 paper- paper twice the size of A4 paper used to draw and write on. Once the equipment had been gathered it was placed and was set-up in the centre of the table. A sheet of plain A3 paper was placed on the table with a light box on top of it. Then light box was connected to the power pack and a 3 ray grate was placed at the end of the ray box. Once the ray box was set-up a convex lens was placed in the centre of the sheet of paper and all the equipment was drawn around. Once the equipment had been drawn around the light ray box was switched on and the light rays were drawn showing the focal point (where the lines met). Then a dotted line was drawn from the lens to the focal point and the line was labelled the focal length. This process was repeated with a concave lens Results As every good scientist knows the results are the main aim of the experiment and recording the results is even more important My results are attached on the A3 pieces of paper. Evaluation I will now evaluate my work to date be referring the aim set at the beginning of the assignment and will evaluate and analyse my performance and accomplishment the objectives. Aim: I will be using a ray box with concave and convex lenses to measure focal points. This will be done by sating up a ray box with a convex/concave lens and shining a ray beams through the lenses and drawing over the beams. With this experiment I hope to acquire the skill of measuring focal points and I will hopefully be able to use this skill later on in higher levels science. Shown above is the initial aim which was stated within the introduction. When I first created this aim I thought I would have an easy journey. As I carried out my experiment, the errors that I encountered were many, to my surprise. However, in the end I successfully carried out the experiment and come out with positive results. Whilst carrying out this experiment I encountered many unexpected errors and I had to overcome them on the spot. As I was conducting my experiment the first error I encountered was that the light box would not turn on. At first I thought it was the power pack and replaced it but that did not seem to work. After replacing the power pack seemed to have no affect I was certain that there was something wrong with the light box so I replaced with another light box but still ended up with sane results as the first time it would not switch on. With changing the power pack and light box there was only one other thing for it the power socket was faulty. With doubt in my head I decided to use another power socket and found that the light box switched on and was working perfectly fine. From here on I did not encounter any other errors. Overall by looking at the problems and potential problems I had I think I didnt carry out a very accurate experiment. With all the minor problems I think the accuracy was not as good as it could have been. I think that the method and the equipment and the materials for this experiment are great for maximum accuracy but they do not eliminate the chance for human error. Over all out of the whole experiment I enjoyed the theory the most due to the fact that it enhanced me knowledge about preparing accurate chemical solutions and it showed me it just wasnt a basic skill but a crucial skill which involved a high level of accuracy I also enjoyed conducting the experiment even though I encountered many errors I enjoyed finding a solution to them. I also think that this experiment has challenged me mentally in every academic way. It has also helped me to develop personal thinking strategies. During this experiment I learnt quote a lot and enhanced my general knowledge of chemicals as a whole and I learnt practical skills of preparing chemical solutions which I will be able to use in the future. Over all this experiment has been an interesting and an enlightening experience which I have gained many skills and much knowledge even though I had encountered many problems I enjoyed the experiment thoroughly and would gladly repeat it.