Electrical conductor Essay Example for Free

Electrical conductor Essay This would increase the resistance of the wire. Another reason why the 60cm wire the highest resistance is that the ammeter and the voltmeter could have been read incorrectly. One reason why the 100cm wire and the 80cm wire had a smaller resistance than the 60cm wire is that the coils of wire could have touched. If this did happen the length of the wire would be shortened. The current would take the easiest route, this being the shorter one meaning the current wont have taken long to travel along the wire. The more coils that touched the more the length of wire would have been shortened. There would have been less collision between the atoms of the wire and the electrons of the current. Also as the current wont have had as far to travel the electrons wont have had to squeeze together for as long as predicted. If this did happen I predict using the graph that the 100cm wire was decreased to an estimated 58cm, and that the 80cm wire was reduced to an estimated 55cm. I cannot prove that this is true, it is just a prediction. The sketch below shows what the graph looked like: The sketch below shows how I expected the graph to look: Evaluation I think that the 60cm, 80cm and the 100cm wires were all anomalous results. I think that all of these results are anomalous because the 60cm wire had a higher resistance than the 80cm and the 100cm wires , however the 80cm and 100cm wires had a lower resistance than the 60cm wire. I cannot tell which of the above statement is correct. The results could be anomalous because the ammeter and voltmeters were read incorrectly. Making the 60cm wire have a higher resistance than it should have had, or resulting in the 80cm and 100cm wires have a lower resistance than it should have had. The coils of wire on the 80cm and the 100cm wire could have touched, resulting in the length of the wire being shortened. This therefore would reduce the resistance of the wire because the current would take the easies route, which is the shortest instead of taking the longest route around the coil. This means that there would have been less collisions between the atoms of the wire and the electrons of the current. Therefore the current would have flowed faster than expected. Also as the electrons wouldnt have had as far to travel as predicted they wouldnt have had to squeeze together for as long, meaning there would have been less collisions between electrons and other electrons. The 60cm wire could have already been used. This means that it could have still held an electrical charge which would increase the resistance of the wire. Also all of the ice in the boiling tube could have melted meaning that the temperature would have increased, resulting in the resistance being increased. If I could repeat the investigation again there would be a number of changes that I would make. One of these changes would to decrease the lengths of the wire. The 100cm wire was too long and it was difficult to wrap the wire around the boiling tube without any of the coils touching. Also I could have used a bigger boiling tube that had a wider diameter. It would be easier to wrap the wire around the boiling tube without any of the coils touching. Also if more repetitions were done there would be less chance of anomalous results appearing. If I did the experiment again I would change the ice after each experiment. Therefore none of the ice would melt completely and the temperature wouldnt rise I dont think that the voltmeter and ammeter were read incorrectly because there are no massive changes in the two reading on the table. If I was to repeat the investigation I would make sure that the wire was new wire that hadnt been previously used and that the wire came from the same strip. I wouldnt change my graph because I fell that it is clear and easy to see where each length of wire is. Bibliography Below is a list of web sites that I used to fin out background knowledge for the investigation: www. essaybank. co. uk www. goggle. com www. sciencefinder. org www. sciencenet. org Here is a list of books that I used in my investigation:Â   Coordinated Science Physics Also I use Encarta 99 to find out information for the investigation.

The Health Benefits of Vegetarianism Essay -- Health Nutrition Diet Ex

The Health Benefits of Vegetarianism Maintaining a well-balanced vegetarian diet is healthy and can be beneficial by reducing the risk of health diseases, particularly cardiovascular diseases and obesity. Vegetarians are individuals who choose to abstain from eating foods derived from animals, such as meat, poultry, fish, and dairy products. This type of a diet is practiced for a variety of reasons, whether out of respect for animals and the environment, for the potentially healthier lifestyle, or simply out of distaste for or allergy to meat products. Practicing vegetarianism is no more difficult or complicated than following a regular meat-inclusive diet; eating a variety of soy, nut, or wheat based products can substitute for certain meat dishes and dairy products and provide the needed nutrients that those normally provides. Vegetarianism is a healthy choice; following a meat-restricting diet can lower cholesterol and fat intake, thus reducing the chances of developing heart diseases and obesity. Despite several misconceptions that claim vegetarianism is unbalanced and thus unhealthy, a vegetarian diet can still meet daily calorie and other nutrient requirements without including meat and dairy products. According to the United States Department of Agriculture, to maintain a healthy lifestyle a person should consume a balanced amount of fruits & vegetables, grains, meat, dairy products, and fats in accordance with the "Food Pyramid." The human body requires a minimum amount of various vitamins, minerals, and nutrients in order to perform properly and carry out bodily functions. Though removing beef, pork, poultry, and other animal-derived foods can leave a diet lacking in protein, calcium, iron, and vitamins... ...hy choice; there are numerous potential benefits that come with following a diet that abstains from meat and dairy products. Though following a vegetarian lifestyle with an unbalanced diet can be just as health hazardous as a meat-inclusive unbalanced diet, a vegetarian regime that maintains the recommended daily nutrients can be healthy and beneficial. A well-balanced vegetarian meal plan can help reduce the risks of heart diseases and obesity. Sources used http://dictionary.reference.com/ http://www.eatright.org/Public/NutritionInformation/92_11722.cfm http://www.epic-oxford.org/ http://www.pueblo.gsa.gov/cic_text/food/food-pyramid/main.htm http://www.vegetarian-diet.info/vegetarian-health-heart-disease.htm http://www.vegetarian-nutrition.info/updates/trends.php http://www.vegsoc.org/health/ http://www.vrg.org/nutshell/nutshell.htm

Analysis of Brick Cleaner Essay

Aim: To find the percentage by mass of hydrochloric acid present in brick cleaner by doing an acid-base titration. Theory/Hypothesis: The main ingredient in brick cleaner is HCL and must be diluted and titrated with a base to be able to analyse it. It reacts with parts of the concrete which allows it to remove the concrete from the bricks. I think there will be around 30% of HCL in brick cleaner. Materials: * 5mL brick cleaner * 100mL, 0.1M standard sodium carbonate solution * 250ml de-ionised water * Methyl orange indicator * 250mL volumetric flask * 4x100mL conical flasks * Small funnel * 10mL measuring cylinder * 20mL pipette * Pipette filter * Dropping pipette * Burette and stand * White tile * Electronic balance * Safety glasses * Gloves Method: 1) A 250 mL volumetric flask was weighed with it’s mass recorded 2) A 10mL measuring cylinder was used to pour 5mL brick cleaner into the volumetric flask. The flask was stoppered straight after all the brick cleaner was in the flask. 3) The flask was then reweighed 4) De-ionised water was added until the flask was about half full. The flask was stoppered and shaken carefully upside down several times. 5) More water was added to the flask about a cm below the graduation line. A dropper was used to accurately drop the right amount of water to the flask so the bottom of the meniscus was on the graduation line. 6) A 20mL pipette was used to put 20mL of sodium carbonate solution into each of the four 100mL conical flask. 3 drops of methyl orange indicator was added to each. 7) The burette was filled with the solution of brick cleaner. 8) The sodium carbonate solution was titrated with the solution of brick cleaner until there was a clear permanent colour change. 9) Steps 7 and 8 were repeated until 3 concordant results were Results: Weight Volumetric flask 78.968g Brick cleaner 6.00g Titre 1 2 3 Initial vol 2.3 23.4 3.0 Final vol 23.4 44.5 24.0 Vol added 21.1 21.1 21.0 Calculations: On page attached. Discussion: The weight for the brick cleaner may not be 6.00g as the volumetric flask was not weighed again with the brick cleaner in it because that step was forgotten. So the result above was taken from another student that did the prac. This will affect the results as the mass of the brick cleaner is used to determine the percentage by mass of HCL in brick cleaner. All 3 titres show that they are only within 0.1 of each other. The hypothesis has been disproved because it was suggested the 30% of HCL would be in brick cleaner and there’s only 2.4% although it’s not certain that those steps were done correctly. There were no problems encountered during this prac. Focus Questions: 8)a) the manufacturer says that brick cleaner is made up of around 35% HCL, which is a massive difference to the answer that was got in this prac but again question 7 was not done correctly. b) differences in class results occur because not everybody would have done the exact volume of brick cleaner, sodium carbonate etc as each other therefore the difference in results obtained. 9) To correctly clean up a spill of 20mL brick cleaner you would mop it up immediately, washing it away with massive amounts of water 10)a) volumetric flask= once with water twice with brick cleaner b) Burette= once with water twice with diluted solution of brick cleaner c) pipette= once with water twice with diluted brick cleaner d) conical flask=once with water twice with sodium carbonate solution Conclusion: To conclude, there should be 35% HCL in brick cleaner although it was found that there was only 2.4%

Scorpion Fish Facts (Scorpaenidae)

The term scorpion fish refers to a group of ray-finned fishes in the family Scorpaenidae. Collectively, they are called rockfish or stonefish because they are bottom dwellers camouflaged to resemble rocks or coral. The family includes 10 subfamilies and at least 388 species. Important genera include the lionfish (Pterois sp.) and stonefish (Synanceia sp.). All scorpion fish have venomous spines, giving the fish their common name. While stings can be fatal to humans, the fish are not aggressive and only sting when threatened or injured. Fast Facts: Scorpion Fish Scientific Name: Scorpaenidae (species include Pterois volitans, Synaceia horrida)Other Names: Lionfish, stonefish, scorpionfish, rockfish, firefish, dragonfish, turkeyfish, stingfish, butterfly codDistinguishing Features: Compressed body with wide mouth and conspicuous, venomous dorsal spinesAverage Size: Under 0.6 meters (2 feet)Diet: CarnivorousLife Span: 15 yearsHabitat: Coastal tropical, subtropical, and temperate seas worldwideConservation Status: Least ConcernKingdom: AnimaliaPhylum: ChordataClass: ActinopterygiiOrder: ScorpaeniformesFamily: ScorpaenidaeFun Fact: Scorpion fish not aggressive. They only sting if they are threatened or injured. Description The scorpion fish has a compressed body with ridges or spines on its head, 11 to 17 dorsal spines, and pectoral fins with well-developed rays. The fish come in all colors. Lionfish are brightly colored, so potential predators can identify them as a threat. Stonefish, on the other hand, have mottled coloring that camouflages them against rocks and coral. The average adult scorpion fish is under 0.6 meters (2 feet) in length. Except for lionfish, scorpion fish have a mottled coloration that serves as camouflage. LITTLE DINOSAUR / Getty Images Distribution Most members of the Scorpaenidae family live in the Indo-Pacific, but species occur worldwide in tropical, subtropical, and temperate seas. Scorpion fish tend to live in shallow coastal water. However, a few species occur as deep as 2200 meters (7200 feet). They are well-camouflaged against reefs, rocks, and sediment, so they spend most of their time near the sea floor. The red lionfish and common lionfish are invasive species in the Caribbean and Atlantic Ocean off the coast of the United States. The only effective method of control to date has been NOAAs campaign of Lionfish as Food. Encouraging consumption of the fish not only helps control lionfish population density, but also helps protect overfished grouper and snapper populations. Reproduction and Life Cycle Female scorpion fish release between 2,000 and 15,000 eggs into the water, which are fertilized by the male. After mating, the adults move away and seek cover to minimize attention from predators. The eggs then float to the surface to minimize predation. Eggs hatch in after two days. The newly-hatched scorpion fish, called fry, remain near the surface until they are around about an inch long. At this time, they sink to the bottom to seek a crevice and begin hunting. Scorpion fish live up to 15 years. Diet and Hunting The carnivorous scorpion fish preys upon other fish (including other scorpion fish), crustaceans, mollusks, and other invertebrates. A scorpion fish will eat virtually any other animal that can be swallowed whole. Most scorpion fish species are nocturnal hunters, while lionfish are most active in the morning daylight hours. Some scorpion fish wait for prey to approach. Lionfish actively hunt and attack prey, using a bilateral swim bladder to precisely control body position. To catch prey, a scorpion fish blows a jet of water toward its victim, disorienting it. If the prey is a fish, the jet of water also causes it to orient against the current so that its facing the scorpion fish. Head-first capture is easier, so this technique improves hunting efficiency. Once the prey is positioned correctly, the scorpion fish sucks in its prey whole. In some cases, the fish uses its spines to stun prey, but this behavior is fairly uncommon. Predators While its likely that predation of eggs and fry is the primary form of natural population control of scorpion fish, its unclear what percentage of scorpion fish young are eaten. Adults have few predators, but sharks, rays, snappers, and sea lions have been observed hunting the fish. Sharks appear to be immune to scorpion fish venom. Although scorpion fish are venomous, they are gentle animals. This diver is feeding a lionfish. Justin Okoye / EyeEm / Getty Images Scorpion fish arent fished commercially because of the risk of stings. However, they are edible, and cooking the fish neutralizes the venom. For sushi, the fish may be eaten raw if the venomous dorsal fins are removed before preparation. Scorpion Fish Venom and Stings Scorpion fish erect their spines and inject venom if they are bitten by a predator, grabbed, or stepped on. The venom contains a mixture of neurotoxins. Typical symptoms of poisoning include intense, throbbing pain that lasts up to 12 hours, peaking in the first hour or two following the sting, as well as redness, bruising, numbness, and swelling at the sting site. Severe reactions include nausea, vomiting, abdominal cramps, tremors, decreased blood pressure, shortness of breath, and abnormal heart rhythms. Paralysis, seizures, and death are possible, but are usually restricted to stonefish poisoning. The young and elderly are more susceptible to the venom than healthy adults. Death is rare, but some people are allergic to the venom and may suffer anaphylactic shock. Australian hospitals keep stonefish anti-venom on hand. For other species and for stonefish first aid, the first step is to remove the victim from water to prevent drowning. Vinegar may be applied to reduce pain, while the venom may be inactivated by immersing the sting site in hot water for 30 to 90 minutes. Tweezers should be used to remove any remaining spines and the area should be scrubbed with soap and water and then flushed with fresh water. Medical care is required for all scorpion fish, lionfish, and stonefish stings, even if the venom appears to be deactivated. Its important to be certain that no spine remnants remain in the flesh. A tetanus booster may be recommended. Conservation Status Most species of scorpion fish have not been evaluated in terms of conservation status. However, the stonefish Synanceia verrucosa and Synanceia horrida are listed as least concern on the IUCN Red List, with stable populations. The luna lionfish Pterois lunulata and red lionfish Pterois volitans are also least concern. The population of red lionfish, an invasive species, is increasing. While no significant threats face scorpion fish at this time, they may be at risk from habitat destruction, pollution, and climate change. Sources Doubilet, David (November 1987). Scorpionfish: Danger in Disguise. National Geographic. Vol. 172 no. 5. pp. 634–643. ISSN 0027-9358Eschmeyer, William N. (1998). Paxton, J.R.; Eschmeyer, W.N., eds. Encyclopedia of Fishes. San Diego: Academic Press. pp. 175–176. ISBN 0-12-547665-5.Morris J.A. Jr., Akins J.L. (2009). Feeding ecology of invasive lionfish (Pterois volitans) in the Bahamian archipelago. Environmental Biology of Fishes. 86 (3): 389–398. doi:10.1007/s10641-009-9538-8Sauners P.R., Taylor P.B. (1959). Venom of the lionfish  Pterois volitans.  American Journal of Physiology.  197: 437–440Taylor, G. (2000). Toxic fish spine injury: Lessons from 11 years experience. South Pacific Underwater Medicine Society Journal. 30 (1). ISSN 0813-1988