This experiment is designed Essay Example for Free

This experiment is designed Essay This is experiment is designed to approximate i , the coefficient of friction, for two surfaces. We used a piece of rubber on the bottom of a wooden block on a wooden table. Assumptions To undertake this experiment, first I developed an equation allowing a straight line to be plotted from our results. This will test if Coulombs law is correct. The main assumptions made in this experiment are: 1. Acceleration is constant 2. The strings are light and inextensible, and the pulley is light and smooth 3. g, gravity is 9. 8 4. Coulombs law is correct 5. There is no air resistance 6. F=ma These assumptions have different weights in affecting our results. Some are more likely to affect our results, whilst others will only have a small effect. Assumption How strong the effect is on results Acceleration is constant This will have a moderate effect on the results. We can see that the acceleration is not constant. This is because friction does change slightly with velocity, and we are ignoring air resistance Light, inextensible strings In fact the strings do stretch slightly, and do have a small weight. This will affect the results as forces will not be constant during the experiment, and therefore produce irregular acceleration. Light, smooth pulley This will affect the results in the same way as above. We attempted to use the smoothest pulley available, but obviously it can never be perfectly smooth. That the pulley has mass does not affect our results, as we are not dependent on the pulleys mass for our results. Gravity is 9. 8 This will introduce a systematic error into our calculations, but as we will use this assumption for both the results and the model, it will not make a difference for our experiment. Coulombs law is correct This will make a big difference to our results. By assuming that , our calculations are fairly simple. However, this linear model is incorrect. This will affect our results considerably, and may results in a curve being plotted from our results instead of a straight line. No air resistance This will have a mild effect on the results. Because the block of wood and the weights are fairly small, the effects of air resistance are negligible. However there will be a small effect, which again may force the results into a curve rather than a straight line. This assumption will not impact our results very much at all. For macroscopic objects, such as we are dealing with, this law is a very good model. However if we were to repeat the experiment using single atoms for the objects, this would be a bad model. To help overcome these systematic errors, we insured that we had the smoothest pulley, and that the surfaces that we used were consistent. In other words, that the table was the same roughness all the way along it, and that the rubber was the same all over. Manipulating the model When m2 is released m1 accelerates. These two objects can be looked at separately. Using . (1) (2) (3) Using (Coulombs Law) (4) Substituting equation 4 into equation 1 Substituting into equation 3 (5) Assuming constant acceleration (see note above) As Substituting into equation 5 The two variables will be m1 and t. By putting , we can cancel m2 from the equation. Setting k to be 1022g (this is the lowest weight for which it will still move) . This is because otherwise m2 hits the floor. .. 1031. 8 should be 9. 8*1022 This allows us to plot a graph with m1 on the x-axis, and on the y-axis. Comparing the above equation with shows us that the gradient should be , and the y-intercept should be 0. 673. 6. 533333333333333333 Conducting the experiment Again, this diagram shows the layout of the experiment. m2 weighs more than m1. When m2 is released m1 accelerates. In my model I assumed that this acceleration is constant. However in reality this is not true. As mentioned previously, this will affect my results. The weight of m1 presses down on the table as the block accelerates. This causes frictional resistance between the block and the bottom of the table. The coefficient of friction between the rubber on the bottom of the block and the table is denoted by ?. By measuring the time taken to move over a specified distance, and by knowing the weight of the two masses it is possible to calculate ?. Following on from the assumptions above, it is possible to attempt to minimise the effects of these modelling approximations. For instance, if it were possible to ensure constant acceleration then doing this would reduce errors, and make the results more accurate. 1. Ensuring that the pulley was as smooth as possible. 2. Ensuring that the table was of equal roughness all the way along it. 3. Making sure that there is no wind or draughts on the block. 4. Making sure that the string is as inextensible as possible. Variation in experimental results As in every experiment, there is variation in the results. This is because in, real life, there are more than two variables changing. For example, random draughts, inaccuracy in timing, inaccuracy in measuring distance, inaccurate weights and differences in the table surface. The error bars on the graph show this error, with the central line showing an average. Comparison between experimental data and predictions of the model The predictions of the model give a line of the equation y = -1. 37x + 13. 8. This gives ? to be 1. 14. This is a lot bigger than our original estimate. In addition, 13. 8 is approximately twice as big as 6. 53. This shows that our experiment does not follow our original model. This is probably due to our assumption that Coulombs Law is true. This model will produce a straight line. Our results show a subtle curvature, implying a non-linear relationship between F and ? r. Although random variation could have created this curve, it seems that it is due to the inaccurate model of Coulombs Law. If the experiment had been based on a non-linear law then a different set of equations would have been derived which would result in a linear function being plotted. Revision of the process To improve the experiment, it would be better to use light gates to improve accuracy for timing. On the results that we collected, the higher speeds resulted in wider error bounds and thus less accuracy. This is because it was a lot harder to accurately measure these fast times. Measuring the distances we were moving over more accurately would also increase accuracy, as would more accurate measurement of mass. However, accuracy is not the main issue in this experiment. For this experiment, it seems that our model is incorrect, rather than the results. To improve this experiment, our assumptions need to be changed. Most assumptions are fine, but the assumption of Coulombs law is very inaccurate. This assumption of a linear relationship forced our results into a curve. To achieve a more meaningful analysis of these results, we need a better model on which to compare them. However, more accurate models for friction are much more complex and far less simple to use.

Almost the Wrestling State Champion :: Memoir Essays

Almost the Wrestling State Champion      Ã‚  Ã‚  Ã‚  Ã‚  There he was, standing one step above me on the platform. He was wearing his maroon colored warm-ups and holding the bracket that the champion always wins. Over the school's announcement system I could hear the announcer saying, "In second place from Hotchkiss, Derek Blitz, and your champion at 103 pounds, from SoRoCo, Josh Deaver." I just stood there hanging my head wondering why he was getting the first place medal and I wasn't. After all, I had worked hard in practice, but in the end I couldn't pull off the win. Now I could only mope around knowing that I had almost won and continue replaying the match over and over again in my head.   Ã‚  Ã‚  Ã‚  Ã‚  On Monday of the week before the tournament, I lost my varsity position in a close challange match. Once that happened, I started to go through the practices without any intensity. All week I was acting like I was practicing as hard as I could, but I was really only putting in enough effort to make sure we didn't have a harder conditioning than normal. Since I had lost my varsity position, I had it stuck in my head that there was no reason to practice very hard. After all, I was going to be wrestling on JV.   Ã‚  Ã‚  Ã‚  Ã‚  On Friday, the coaches told us to be at the high school by 6:15 the next morning, so that we could make it to Paonia for weigh-ins at 7:00. The next morning I arrived at the high school by 6:00, and then I went into the locker room to make sure that I hadn't forgotten anything. By the time we arrived at Paonia, it was almost time for weigh-ins. A referee walked out into the gym and called all 103 pounders to the wrestling room. I walked up to the scale where two other refs were waiting to make sure no one had long nails or ring worm. Next, I proceeded to step on the scale to see if I would make weight. The ref, who was at the scale, then said, "102 pounds, step off." A huge feeling of relief swept over me, and I soon realized that I was going to give 110% to wrestling that day.   Ã‚  Ã‚  Ã‚  Ã‚  At about 9:00, the tournament began and I was on the first open mat against the 103 pounder from Middle Park. I looked over my opponent and said to myself, "I am going to win this match.

Nutrition Assignment Essay

Cooking is the application of one of two types of heat. Name them and then classify all the methods of cooking (baking, blanching etc) listed in your course according to which type of heat they use. Cooking is the application of one of two types of heats which are using moist or dry methods of cooking. Baking: Baking is a commonly used cooking technique that applies dry heat to a food, along with an air flow. It avoids the problems of nutrient loss due to leeching, and is effective at breaking down starches. However, heat labile nutrients will be destroyed and the long cooking time will negatively affect nutrient value. Baked goods loose moisture and tend to be dry; fats will leech out as well. Blanching: Blanching is the plunging of a food item into boiling water for a very short time period, before removing it and transferring it to cold or icy water. The cold water stops the cooking process. Blanching can remove the bitter taste from some vegetables and can also enhance their colour, making them more appealing. The application of very high heat will kill many micro-organisms and will also soften the tough fibres in vegetables. Braising: A method of cooking that is similar to baking, however, a liquid is placed beneath the food, or the food placed in a liquid. The liquid, at high temperatures, will convert to steam and so the food will be partially baked and partially steamed. It is used primarily in the preparation of meat dishes, where the tough collagen fibres require high heat and time to become softened and palatable. This of course impacts on the level of heat labile nutrients in the food, and leeching may also be a problem in the early stages of cooking. High temperatures will seal foods quickly, helping to trap juices and the nutrients within them to some extent. Other terms for braising include stewing or pot-roasting. Casserole and stews are braised dishes. When the meat is kept in the fluid, or the fluid returned to the meat nutrient losses will be lessened. Grilling: Grilling, like baking, is a dry cooking method, the difference being that grilling is the direct application of heat to the food as opposed to hot air. Food is generally cooked very quickly, which is good for limiting nutrient degradation, but at very high heat, which causes loss of the heat labile nutrients. Barbecuing, cooking over hot coals or charcoals are all consider variations of grilling. With larger cuts of meat, cooking time is lengthened, resulting in additional nutrient loss. Poaching or Boiling: Poaching, as opposed to boiling, is the gentle heating of a food in water. Typically, an acid is also added to the water (wine, vinegar, citrus juice) and this can impact on acid/pH sensitive vitamins such as vitamin K. Leaching is of course a major source of nutrient loss, but as the heat is lower; B group vitamins should remain intact as the temperature is below 100C. Mineral content is not dramatically altered with poaching or boiling but is more apparent than other cooking methods. Comment on the ease/difficulty for a person, suffering the medical condition you investigated, who has to stick to the dietary guidelines you created in question 7. Write a paragraph. If a person is naturally used to eating healthy following the crohn’s diet might be easy to follow for a person. Fatty and oily foods must be avoided all together as they are difficult to digest when a person has this medical condition. Eating a softer and blander diet is also essential to avoid discomfort. Sometimes bland foods are hard to follow as they are boring to an individual this can be hard to follow. Coffee lovers might also find it hard as caffeine can irritate the stomach as well. References http://www.heartfoundation.org.au/healthy-eating/mums-united/healthy-eating/Pages/default.aspx?gclid=CPKCw6rk5rMCFUhZpQodSn0AXg http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/behavior.htm http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Weight_loss_a_healthy_approach http://www.aafp.org/afp/2003/0415/p1769.html http://www.diabetes.co.uk/diet-basics.html http://www.livestrong.com/article/426491-nutritional-requirements-for-diabetics/#ixzz2D7F4J47I http://www.livestrong.com/article/286671-diet-for-gastric-problems/ http://www.livestrong.com/exercises-for-obese-people/ http://www.kitchensavvy.com/journal/2006/03/blanching_food.html http://www.bbc.co.uk/health/treatments/healthy_living/your_weight/whatis_bmi.shtml http://www.arhp.org/publications-and-resources/quick-reference-guide-for-clinicians/postpartum-counseling/diet Course Notes http://www.trimdownclub.com/introduction/index.html?ad=311 Health Magazines have also been investigated.

Meli Marine An Important Decision For The Company Essay

Introduction This essay contains five critical questions derived from the analysis of the case ‘Meli Marine’ by applying the relevant principles to help the CEO of Meli Marine make an important decision for the company. Critical questions 1. What’s Meli’s budget of entering the Asia-North America market? 2. What are the strengths and weaknesses of Meli Marine? 3. What are the risks and obstacles of this move? 4. Does the 16 vessels and their capacities suit best for the Asia-North America market? 5. Could Meli Marine continue using the customer-centric service strategy in the Asia-North America market? Justification and discussion of relative effectiveness of critical questions 1. ‘An investment is made to earn a return’ (Trotman, Gibbins and Carson 2012, p. 652). In order to make a sensible investment with adequate consideration of the company’s profitability, it would be vital for company to figure out both the budget for investment and the estimate revenue to see whether the move is commercially doable. There are also estimate costs which need to be focused on. If the potential expenses of an investing action tend to be much higher than budget, it might impel the company to bear liability pressure, or to give up the investment. The case noted that Meli Marine was given the opportunity to purchase the 16 vessels and enter the Asia-North America market. Buying ships seemed to be the first step of investment in this move, which would be followed by significant itemsShow MoreRelatedThe Impact Of Meli Marine On The Container Shipping Value Chain Essay889 Words   |  4 PagesIntroduction Meli Marine is a Singapore-based marine transport company which now has an opportunity to purchase 16 vessels from Teeh-Sah company to enter Asia-North America shipping market. The CEO of Meli Marine is wondering whether the move is right for the development of company. Some questions are designed to help him to make proper decisions. Besides, reasons in terms of the questions are justified in the following. Critical questions 1.Why the vessels price that Teeh-Sah gives is consideredRead Moreâ€Å"Implicit† and â€Å"Explicit† Csr: a Conceptual Framework for a Comparative Understanding of Corporate Social Responsibility13330 Words   |  54 Pagesattributed, and ready to claim, social responsibilities, this has not been so common elsewhere. Comparative research in CSR between Europe and the United State has identified remarkable differences between companies on each side of the Atlantic. This pertains, first, to the language companies use in describing their involvement in society. In a comparative study of corporate self-presentaWe thank former associate editor Thomas Donaldson and the anonymous reviewers for their input and support in developing