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IB diploma Physics HL IA

How does change in water level affect the pressure difference required to pump the water out of a bottle?IntroductionSince I was very young, I have watched television documentaries on life in Africa with my grandmother. The world I have experienced through the documentary was stunning; people built their own hut as a shelter, harvested fruits from trees, and pumped out water from a public well.The scene of pumping water from wells astonished me. I didn’t realize that, in most developing countries, getting water was such a tough task. Although, water pumps were used to irrigate water from places to places, people still had difficulties getting water when wells almost ran out of the water. When I watched the people struggling to pump up the water from the bottom of the deep well, a question arose. Does it really take more effort to pump out the water from the very bottom of a well than from the top? How much more effort should people make to pump water as the water level decreases to thepoints within the fluid column.According to the equation above, the pressure difference required to pump the water would have a directly proportional relationship with the distance the water travels along the tube.However, if the gas pumped into the bottle is released due to loose setup of the pump, water level in the tube would be varying; the water could be flowing when the pressure is measured at the spout. Then, Bernoulli’s principle applies to this investigation. Bernoulli’s principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy.As shown in the equation above, if the gas is not perfectly sealed in the water bottle, the pressure difference would not be directly proportional to the water elevation. The y-values, the pressure differences, would become slightly smaller, forming a negative y-intercept.HypothesisAccording to the equation of, the water level, h1, would have a negatively protainty is larger because the difference in pressure is relatively small. Thus, I repeated the experiment 10 times for each value of the independent variable to get more accurate values. Because I have to press the ‘Keep’ button to record the value, the values vary depending on when I press the button. I had to press ‘Keep’ exactly when the water is at the spout because there is a change in pressure when the water is not yet raised to the maximum height or when it already flowed out of the spout. In such experiment with large uncertainties, more repeats are required to reduce the random errors. I collected 12 data points to get a clear relationship between the two variables and to identify the shape of the curve. The use of gas pressure sensor logger pro helped me to collect 10 repeats efficiently.AnalysisRaw DataPressure (±0.02kPa)original pressure (±0.02kPa)water level (±0.3cm)Trial 1Trial 2Trial 3Trial 4Trial 5Trial 6Trial 7Trial 8Trial 9Trial 10102.703.00106.92106.83107.17107.13107.ter elevation. Then the relationship between the pressure difference and water level could be derived as,Thus, the gradient of the graph, Pa/m, shows how much change in water level affect the pressure required to pump the water and represents the product of fluid density and acceleration due to gravity. Ideally, accepted value of the gradient should beThe gradient calculated in my experiment is less (more negative) than the theoretic value from the equation mentioned in the background information. The accepted value of the gradient does not fit in the range of the gradient from my experiment. This indicates that my experiment was not accurate due to many systematic errors.My y-intercept in Graph 1-1, , represents the pressure required when the water level is zero. Although water can’t be pumped when the water level is zero, this value is a calculated value for an extreme situation, showing the pressure used to transport the water for the entire length of the tube, which is 46cm. My intred would also changes. The velocity can be either larger or smaller for each experiment. It is a random error and the pressure difference can be larger or smaller than the actual value.Either replacing the plastic valve in the pump or replacing the hand pump with an electric pump. The use of electric pump would reduce the reaction time, so the velocity of water at the spout can be kept zero.Temperature change affects the density of the gas.Because the experiment was carried throughout several days, the temperature was not constant every day. When the temperature varies, the density of the gas varies along with its volume. The change in volume causes the water level to change; this random error can either increase or decrease the pressure difference.Either collecting all the data on one single day or keeping the same temperature for each experiment would reduce the random errors.Horizontal displacement of the tube in the bottle (not perpendicular to the bottom of the bottle)Because theAT 1

자연과학| 2020.05.11| 12페이지| 6,000원| 조회(228)

Water, data, IB, Physics, IA, Bernoulli, Press..

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IB diploma Economics SL International IA

IB ECONOMICSINTERNAL ASSESSMENTCOMMENTARY COVERSHEETName***Candidate Number***Teacher***Source of the news(full hyperlink)http://www.ckom.com/syn/648/170441/industry-farmers-react-as-india-targets-pea-imports/News headlineIndustry, farmers react as India targets pea importsDate of news9th November, 2017Date of commentary5th February, 2018Word Count(max 750 Words)750Commentary Number3Area of syllabusInternational EconomicsChecklistIs the work in the right order?i coversheetii newsiii commentaryIs the news within the correct time frame?Are diagrams included?It is within the word count?Have you kept to the IB academic honesty policy?Industry, farmers react as India targets pea importsA surprise move by a major customer has created concerns for Canadian farmers and industry groups.India announced Wednesday that it would apply a 50 per cent import tariff on foreign peas.The country has imported over 1 million tonnes of Canadian peas in each of the last five years, according to Pulse Canada ad also made arrangements to visit the country prior to Wednesday’s announcement.“So it certainly adds some sense of urgency to have this discussion. And that’s really where we’ll look to Ottawa to provide the direction as to how they’re going to react and respond to this change,” he said.‘These peas will find a home one way or another:’ APASPresident of the Agricultural Producers Association of Saskatchewan, Todd Lewis, said this was quite the shock for producers.“In the past I think the highest tariff was 10 per cent,” said Lewis. “This is one of the ones that really came out from left field, certainly anything at 50 per cent is going to make it pretty hard to put Canadian peas to that market.”However, Lewis said India isn’t Canada’s only export market so farmers will be able to export their peas elsewhere.“(Our) provincial and federal governments, along with grower groups like Pulse Canada and (Pulse) Saskatchewan, have done a great job of market development,” he said.Lewis said thaulses and that producers will find a different market to ship them to if need be.Sask. Farmer not worriedBen Wilson has cattle and farms a mixed crop just south of Saskatoon. He said the news from India wasn’t a shock for him.“I haven’t been farming very long, but I have been doing it long enough to see stuff like this come up before,” Wilson said. “We just had a tariff lifted on Canola basically here a year-and-a-half ago so it’s something I’ve seen come before and I guess you kinda just adjust to it when it happens.”Wilson said there’s a chance he might be changing up next year’s plant with a few less acres of peas. He added he’s more concerned about what he has stored in the bins right now.“I talked to my Viterra agent out of Saskatoon today and he was saying they’ve kinda seen this coming for a while and they haven’t even been able to move any peas that they got last fall off the combine yet.”Wilson added he’s not worried in the long run as there’s pea processing plants in Saskatchuce and sell a larger quantity, Q2, of peas, as they have a competitive advantage on price. Thus, with increased sales, domestic producers can earn a higher revenue. Furthermore, the tariff allows the Indian government to gain from the tariff revenues of (Q3-Q2)(Pw+t-Pw), as shown in R. This gain in government revenue allows increased funding to improve public goods and services, such as building infrastructure, which promotes economic growth.However, imposing tariff creates welfare loss in the Indian economy. Consumer surplus is the difference between the highest prices consumers are willing to pay for a good and the price actually paid: thus, it is indicated by the area between the demand curve and price level. After the imposition of the tariff, consumer surplus decreases from C to A and producer surplus increases from D to B. As a whole, social surplus drops from C+D to A+B, leaving P and Q as welfare loss, as R is regained as government revenue. The increase in inefficient product also provides an affordable price for domestic consumers, as the price remains at the world price, Pw, rather than rising to Ps.On balance, although tariff is beneficial to domestic producers, other stakeholders such as domestic consumers face increased price levels, which become a burden to their households. Production inefficiency was also a negative influence: domestic price is higher than the world price because inefficient domestic producers produce goods with a waste of scarce resources, as they have a comparative disadvantage compared to efficient foreign producers. In the long run, imposing such a huge tariff might “hurt the relationship with other trading countries” because India is blocking Canada’s peas to its market. This can harm Canada’s pea market and affect the relationship between two countries. Providing production subsidies, on the other hand, can not only help domestic producers but also support domestic consumers in India, as they benefit from the lowered price lef.

경영/경제| 2020.05.11| 6페이지| 4,000원| 조회(105)

IB, economics, IA, SL, macro, Microeconomics, econ

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IB diploma Economics SL macro IA

IB Economics—internal assessment coversheetSchool code Name of school** ** BEIJINGCandidate name***Candidate number***Teacher***Title of the articleThe IMF cuts its U.S. growth forecast, citing Trump’s unfulfilled promises.Source of the articleThe Washington Post:https://www.washingtonpost.com/news/wonk/wp/2017/07/24/the-imf-cuts-its-u-s-growth-forecast-citing-trumps-unfulfilled-promises/?utm_term=.68b95d769406Date the article was published24 July 2017Date the commentary was written19 September 2017Word count(750 words maximum)750 wordsSection of the syllabus the article relates to (please delete the other 3 options and leave the one you want)Section 2: MacroeconomicsThe IMF cuts its U.S. growth forecast, citing Trump’s unfulfilled promises.The International Monetary Fund has decreased its estimate of how fast the U.S. economy will grow in coming years, a change the organization said reflects doubts about President Trump's ability to deliver on his planned agenda of tax cuts and new inut while the administration has moved quickly to slash regulations on businesses, its plans for tax cuts have been bogged down by clashes in Congress and the administration over health care and other issues. The White House on Monday reiterated the administration is optimistic about its ability to achieve its 3 percent growth target.The IMF said U.S. economic growth could pick up if the administration implements measures like overhauling the tax code — yet it could also fall if Trump’s budget, which consolidates many parts of the government as part of an overall spending reduction, is approved.The fund also cautioned that government measures in the United States and Britain’s post-Brexit negotiations could end up worsening the current environment of policy uncertainty, harming private investment and weakening growth. It warned that the failure to make growth inclusive could lead to the further spread of protectionism, which could disrupt global supply chains and lower growth.Even so, tpublicized target of doubling China’s economy by 2020. Yet it said that such lending could increase the risks to China’s economy in the medium term, as debt continues to build up.The fund also said that steady interest rate hikes in the United States could post a risk to growth by making lending more difficult. Higher interest rates, which mean investors get a better return on their investment, could also trigger a flow of capital out of emerging economies into the United States, which could push up the U.S. dollar and strain emerging economies.The U.S. Federal Reserve is in the process of gradually raising U.S. interest rates to a more normal level after cutting them to stimulate the economy after the recession. In June, the Fed raised its benchmark interest rate by a quarter-point, the third such increase in six months.Fed officials will meet again this week to discuss further rate hikes, but most market observers expect the Fed to delay any further rate increases until the end of thn infrastructure. As shown in Figure 1, the U.S. economy was initially at point A with Yrec and PL1; increased government spending, a component of AD, will shift AD curve outward from AD1 to AD2 in short run. Trump’s “ambitious plan to use tax cuts” will also contribute to increasing levels of AD. When corporate tax is lowered, firms have higher total revenue after tax and thus will be motivated to spend more on capital investments, which will not only increase AD but also lead to innovation and improvements in product quality. With decreased income tax, consumers have more disposable income: thus, consumers have incentives to increase their consumption levels. Increases in government spending, investment, and consumption lead to a new equilibrium point B, where real GDP is increased from Yrec to Yp, eliminating the recessionary gap and achieving economic growth.Meanwhile, during this process, price level is increased from PL1 to PL2, leading to inflation: a sustained increase in the g the economy can access infrastructure with lower cost and effort, thus shifting LRAS1 to LRAS2. However, it is difficult for the government to estimate which area to invest in to maximize the rightward shift of LRAS; the extent to which improvements in infrastructure can effectively influence the supply curve is unpredictable. As mentioned in the article that the government’s “plans for tax cuts have been bogged down by clashes in Congress and the administration over health care and other issues”, if misjudged, vast amounts of government spending on infrastructure may only become a waste of resources, without leading to economic growth.The IMF’s decision of having “reduced [growth] forecasts for both 2017 and 2018 to 2.1 percent” seem quite reasonable. This is because increased government spending along with tax cuts could cause a budget deficit, which is when government expenditure is greater than government revenue. To increase government spending in a budget deficit, the government.

경영/경제| 2020.05.11| 7페이지| 4,000원| 조회(140)

IB, economics, IA, macroeconomics, SL, macro, econ

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Exploration of the optimal design of blood vessels that minimizes the cost function

ex)Table of contentIntroductionBranching versus bifurcationAssumptionTheoryOptimal branching angle in relation to the radii of vesselsOptimal bifurcation angle in relation to the radii of vessels-Shifts along AO-Shifts along BO-Shifts along COConclusionBibliographyIntroductionThe vascular system, or the circulatory system, is an organ system that allows blood to circulate and transport nutrients, oxygen, and blood cells in the body to provide nourishment. The system is made up of vessels that carry blood through the body: arteries, veins, and capillaries.It was not until I first had a peripheral intravenous, or IV, placed on my hand that I had more than just a passing interest in the human body’s vascular system. When I went to a hospital to get an IV therapy, I saw a nurse who seemed to be less experienced, observing the back of my hand for a few seconds. Then, she cautiously gave me an injection, penetrating one of my ‘pale blue’ vessel branches. When I asked her what she was lookingels have uniform shape with a constant circular cross-section area throughout the body over time.TheoryFigure SEQ Figure * ARABIC 3 Blood flow along the blood vesselAs assumed above, I modelled the blood vessel as a cylinder, which has a uniform radius r. As shown in Figure 3, there is a pressure difference from one end to the other, forming a driving force to make blood flow. As illustrated in Figure 4, due to the viscosity of blood, laminar flow, which occurs when the blood flows in parallel layers, with no disruptions between them, also exists in blood vessels. The velocity of flow at the surface is zero, and the velocity along the cross-sectional center of the vessel is at maximum.Figure SEQ Figure * ARABIC 4 (Laminar flow, 2017)In Figure 3, the viscous force , which is caused by adhesive forces between fluid and surface, acts against the driving force, . The driving force on the cylinder due to the pressure difference is,(1)where equals to the cross sectional area of the blood vre 6.Figure SEQ Figure * ARABIC 6 Branching blood vesselNote that BC is perpendicular to AB, and the optimal angle that we are trying to find is , or COB. Also, distances are denoted as AO=L1, OC=L2, AB=a, BC=b.The total resistance Y over AOC can be expressed as:The constant value, , in (6) can be expressed as:As shown in the equation (6), we know that resistance is proportional to length of vessel and inversely proportional to the fourth power of radius. Thus, the total resistance is,In order to find out the relationship between the optimal branching angle and the total resistance, we can express the lengths in terms of the angle in Figure 3.(7)Graph SEQ Graph * ARABIC 1 A sine curve (y=sin) Graph SEQ Graph * ARABIC 2 A cosecant curve (y=csc)From Graph 1, we can see that when (blood vessels remain straight and do not branch), would equal 0, and as shown in Graph 2, would not be defined, so as the function Y in (7). This implies that it is not ideal for our blood vessel to be in oneion can be expressed as,(9)The equation (9) shows the relationship between the cost function and the radius of a blood vessel. To find the optimal radius for a given length and flow, the cost function should be minimized. Thus, we can differentiate the cost function driven with respect to the radius r and find the radius when the differentiated value equals zero.To confirm that the is the optimal radius that minimizes the function, we need to use the second derivative test to see if the second differential is a positive value when is substituted.Thus, we can confirm that the optimal radius isBy substituting the optimal radius, , back to the original cost function, we get the minimum cost function.Since we have the minimum cost function of blood vessels in terms of the radius, we can figure out the optimal bifurcation angle. The optimal angle would be the angle where the entire cost function is minimum.Figure SEQ Figure * ARABIC 8 A blood vessel bifurcating into two smaller vesselsIn F out the angle that minimizes the cost function.As shown in the calculations above, I have derived a relationship between the optimal branching angle and the radii of vessels by establishing a cost function for both of the cases, branching and bifurcation. The optimal branching angle is expressed as , and the bifurcation angle as or . These equations show that we are able to find out the optimal branching angles if we know the radii of blood vessels.This application of mathematics can have a significant influence on the study of vascular system and can even stimulate further development of medical science. As blood vessels are distributed throughout our bodies, the vascular system is considered to have a great influence on human bodies. Many factors such as a build-up of fatty deposits can narrow blood vessels, depleting the supply of oxygen-rich blood to affected parts of the body. Also, some abnormal structures of blood vessels can also cause heart disease. Thus, the application of m

수학| 2020.05.11| 17페이지| 7,000원| 조회(254)

IB, IA, Math, function, mathematics, IB Diplo..

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IB diploma Economics SL micro IA

IB Economics—internal assessment coversheetSchool code Name of school*** *** BEIJINGCandidate name***Candidate numberTeacher***Title of the articleCanada will tax carbon emissions to meet Paris climate agreement targetsSource of the articleThe Guardian: Hyperlink "https://www.theguardian.com/world/2016/oct/03/canada-carbon-emissions-tax-paris-climate-agreement" https://www.theguardian.com/world/2016/oct/03/canada-carbon-emissions-tax-paris-climate-agreementDate the article was published3 October 2016Date the commentary was written28 February 2017Word count(750 words maximum)742 wordsSection of the syllabus the article relates to (please delete the other 3 options and leave the one you want)Section 1: MicroeconomicsCanada will tax carbon emissions to meet Paris climate agreement targetsThe Canadian prime minister, Justin Trudeau, said on Monday that Hyperlink "https://www.theguardian.com/world/canada" Canada will impose a tax on carbon emissions starting in 2018 as part of its efforts tu told the Commons. “It is real and it is everywhere. We cannot undo the last 10 years of inaction. What we can do is make a real and honest effort – today and every day – to protect the health of our environment, and with it, the health of all Canadians.”Trudeau argued that Hyperlink "https://www.theguardian.com/sustainable-business/2016/jul/28/canada-emissions-climate-change-justin-trudeau-corporate-business" pricing carbon pollution will give Canada a “significant advantage” in building a cleaner economy, compel businesses to develop innovative ways to reduce emissions, and create hundreds of thousands of clean technology jobs.The Saskatchewan premier, Brad Wall, blasted Trudeau for unilaterally announcing his plan and not working with the provinces on a collaborative proposal. Provincial environment ministers were meeting with their federal counterpart when Trudeau surprised many with his announcement.“The level of disrespect shown by the prime minister and his government is stunniobjects to the higher costs of Trudeau’s plans in later years.Canada’s most populous provinces, Ontario and Quebec, are joining in a cap-and-trade program. British Columbia already has a carbon tax.Trudeau said: “85% of the Canadian economy is located in provinces where there is pricing on carbon pollution in one shape or another. We are going to bring that up to 100%.”Soomin Hwang (Economics SL) Word count: 742Governments may employ market-based policies such as indirect tax imposition to correct negative production externality, negative spillover effects to a third party of production. A carbon tax is a tax applied per unit of carbon emissions, hence creating incentives for producers to reduce their carbon emissions.Justin Trudeau, the Canadian prime minister, said “provinces and territories can either put a direct tax on carbon emissions of at least $10 Canadian ($7.60) a ton or adopt a cap-and-trade system” to meet targets set by Paris climate change accord. However, there was an imand of fossil fuel. As fossil fuels dominate the Canadian market, and renewable energies are less developed, large dependency on fossil fuels makes its demand price inelastic. In the long run, on the other hand, consumers would prefer substitute goods due to the significant rise in fossil fuel price. Substitute goods can be defined as different goods that satisfy the same needs of consumers and, therefore, can be used to replace one another. The demand for substitute goods, renewable energies for example, will rise, increasing the price of renewable energies. The increased price signals producers to increase the supply of renewable energies. Therefore, as shown in Fig 2, the demand of fossil fuels will shift leftward from D1 to D2, decreasing the market quantity of fossil fuel from Qt to Q3, which consequently decreases a significant amount of carbon emission.In Fig 1, as the supply curve shifts leftward from S1 to S2, the producers have to pay for the tax, which is (Pe-Pp)Qt, and conion levels, there are difficulties in designing a tax equal in value to the amount of pollution. It is hard to identify the harmful pollutants and quantify the monetary value of the harm. Brad Wall, the Saskatchewan premier, argued that “This new tax will damage our economy. The bottom line is that the Saskatchewan economy, […] will be one of the hardest hit by a new federal carbon tax because of our trade-exposed resource industries.” As he mentioned, the carbon tax would substantially burden producers, and the society will be harmed ultimately, creating tradeoff between economic efficiency (social optimum) and costs for normal Canadians. Not only producers, but workers are worse off because many factories depend on fossil fuels. The rising tax will force the producers to produce less; fewer workers are needed, leading to unemployment. Consumers are also burdened by increased price of fossil fuels due to carbon tax and rising price of renewable energies.To some extent, Trudeau’s annout.

경영/경제| 2020.05.11| 6페이지| 4,000원| 조회(144)

IB, economics, IA, SL, macro, Microeconomics, econ

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