Total drag and its variation with altitude Essay Example

Total drag and its variation with altitude Paper The equation for total drag is: D = CD x S x ? rV2 (Preston, R) where, CD is the coefficient of drag. It must be subdivided into two parts, the Cdi (Coefficient of induced drag) and CDp (Coefficient of parasite drag. ). Therefore it can be written as: D = (Cdi + Cdp) x S x ? rV2 (Preston, R) The airplanes total drag determines the amount of thrust required at a given airspeed. Thrust must equal drag in steady flight. Lift and drag vary directly with the density of the air. As air density increases, lift and drag increase and as air density decreases, lift and drag decrease. Thus, both lift and drag will decrease at higher altitudes. Fig 1 shows the total drag curve which represents drag against velocity of the object. The fuel-flow versus velocity graph for an air graph is derived from this graph, and generally looks as shown in Fig 2 From the above drag it is seen that the total drag is minimum at a certain velocity. This occurs when the parasitic drag is equal to the induced drag. Below this speed induced drag dominates, and above this speed parasite drag dominates. Design engineers are interested in minimizing the total drag. Unfortunately many factors may conflict. We will write a custom essay sample on Total drag and its variation with altitude specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Total drag and its variation with altitude specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Total drag and its variation with altitude specifically for you FOR ONLY $16.38 $13.9/page Hire Writer For example, longer wing span reduces induced drag, but the larger frontal area usually means a higher coefficient of parasite drag. Conversely, a high wing loading (i. e. a small wing) with a small aspect ratio produces the lowest possible parasite drag but unfortunately is the produces for a lot of induced drag. In recent time it is seen that jet airliners have longer wings, to reduce induced drag, and then fly at higher altitudes to reduce the parasite drag. This causes no improvement in aerodynamic efficiency, but the higher altitudes do result in more efficient engine operation. (Preston, R) Angle of Attack (AOA), is the angle between the wing and the relative wind. Everything else being costant, an increase in AOA results in an increase in lift. This increase continues until the stall AOA is reached then the trend reverses itself and an increase in AOA results in decreased lift. The pilot uses the elevators to change the angle of attack until the wings produce the lift necessary for the desired maneuver. Besides AOA other factors also contribute to the production of lift, like relative wind velocity and air density i. e. temperature and altitude. Changing the size or shape of the wing (lowering the flaps) will also change the production of lift. Airspeed is absolutely necessary to produce lift. If there is no airflow past the wing, no air can be diverted downward. At low airspeed, the wing must fly at a high AOA to divert enough air downward to produce adequate lift. As airspeed increases, the wing can fly at lower AOAs to produce the needed lift. This is why airplanes flying relatively slow must be nose high (like an airliner just before landing or just as it takes off) but at high airspeeds fly with the fuselage fairly level. The key is that the wings dont have to divert fast moving air down nearly as much as they do to slow moving air. Air density also contributes to the wings ability to produce lift. This is manifested primarily in an increase in altitude, which decreases air density. As the density decreases, the wing must push a greater volume of air downward by flying faster or push it down harder by increasing the angle of attack. This is why aircraft that fly very high must either go very fast e. g. Mach 3, or must have a very large wing for its weight. This is why the large passenger airplanes cruise at higher altitude to reduce drag, and hence save on the furl costs. (â€Å"Aircraft for Amateurs†, 1999) Small sized aircrafts have lower than normal Reynolds number. The drag coefficient attributable to skin friction is hence higher for the small aircraft. For this reason, the maximum lift-drag ratios characteristic of business jet aircraft tend to be lower than those of the large transports. Hence, the smaller flights can fly at relatively lower altitudes. References Books John A. Roberson Clayton T. Crowe, 1997, Engineering fluid Mechanics, 6th ed. , John Weily Sons Inc., ISBN 0-471-14735-4. Clement Klienstreuer, 1997, Engineering Fluid Dynamics, Cambridge University Press, ISBN 0-521-49670-5 Websites â€Å"Aircraft for Amateurs†, 11th Jan. 1999 http://www. fas. org/man/dod-101/sys/ac/intro. htm Benson, T. , â€Å"The Beginner’s guide to Aeronautics†. , 14th March 2006 http://www. grc. nasa. gov/WWW/K-12/////airplane/ Johnston, D. , â€Å"Drag†, http://www. centennialofflight. gov/essay/Theories_of_Flight/drag/TH4. htm â€Å"Parasitic Drag†, http://adg. stanford. edu/aa241/drag/parasitedrag. html Preston, R. , â€Å"Total Drag† and â€Å"Flight Controls†, http://selair. selkirk. bc. ca/aerodynamics1/

The little zombies first Professor Ramos Blog

The little zombies first For as long as I can remember I have always had a love for scary things and makeup. Around the age of 12 I started to get into special effects makeup like in the horror movies. Making burns, bruises and cuts was a typical Saturday for me. Within the first few months of dabbling in special FX makeup, my mom showed me an ad for the â€Å"IE Zombie Beauty Pageant†. This was basically a beauty pageant but as a zombie,contestants had to be in full zombie makeup and complete the opening, talent, Q and A and evening gown portion of the competition. As soon as she told me about it I started working on my zombies background, how I got infected and just really building up my backstory. Our first meeting was very nerve racking for me, I was so excited then getting incredibly nervous when I saw the people I was competing against. I had only been doing this kinda makeup for not even 5 months and now I was entertaining a contest with grown women (me being the youngest and the second younges t was 21), I thought â€Å" These women have probably been doing makeup for as long as I have been alive, there was no way I could really compete with them†. The fear of my makeup looking like a total amateur made my stomach drop and my heart just stop. â€Å"I really did not think this through† I thought to myself, â€Å"No way was I was going to go through with this†, the embarrassment was too much. I stayed for the rest of the meeting to see what this thing was really about. We had dance routines and costume changes it was so overwhelming and no one even mentioned the makeup not once. Later after going home going over the schedule again and again really contemplating if I was going to do this I saw the first mention of the makeup. I initially just wanted to it for the makeup, thinking we might have workshops or something to do with even the basics of makeup basics but no. Makeup was all self done or if you were lucky enough like the eventual winner and the runner up you knew someone who could do your makeup professionally. I was not so lucky. So after school I would hurry home do my homework then practice some makeup, hurry take it all off then goto rehearsal (which was 3 hours long) then come home around 11 at night then restart everything the next day. It was a month of rehearsal and it was the longest month of my life. For the first time I wanted October to be over. I didn’t feel I made ANY improvement on my makeup and that I would make the biggest fool of myself. I had been YouTubing and recreating the same look over and over again using extremely forei gn materials like liquid latex, molding clay, spearmint glue and even attempting several times to make my own body paint. (I was on an extremely strict budget) I was clueless on the process, just knowing my very basics of colors and trying to remember when I mix this and that it makes it look like this. It was coming down to the last two weeks before the pageant everything was getting real now.   MTv was following around one of the contestants, doing behind the scenes of everything. I knew I was going to be on tv, but the thought of the off chance that my makeup might be sent me through a whirlpool of emotions. They wanted us to help get the word out, wanting us to go downtown with full face of makeup and pass out flyers. This was it I thought, everyone is going to see how tragic my makeup was, I was just going to drop out so I didnt have to embarrass myself more than I was going to tonight. Right after getting   home I started on my makeup. Damn I thought â€Å"I only practiced the same look and I couldnt copy the same look for the pageant:† I was so lost, how many zombie looks could there be? So I quickly googled zombie and the first thing that came up I tried so incredibly hard to recreate on the spot, spending almost 2 hours doing it. Starting then redoing certain cut s or burns, putting a hairdryer to my face trying to make the latex dry without catching it or myself on fire. Finally this was as good as it was going to get. My pale face with blue and green hues all over, ash black burns on my forehead and scar on my neck. I didnt look completely hopeless, wishing that was the case. After being down there for less than five minutes the unimaginable happened, people were approaching me, complimenting me. They actually thought it was good, they liked it. Telling me how disgusting it was and how scary I looked (these were the best complements I could ever ask for) asking who did my makeup and being in total Awe when I told them I did it. Under all that zombie makeup was an extremely happy little girl. Even if they were lying just to make me feel better at that moment I felt something that I hadnt felt in the longest time, confidence. Those total strangers gave me the courage to go through with the pageant. The day of the pageant was the first time we did   an actual dress rehearsal, full makeup and costumes. This is it I thought â€Å"time to make a complete fool of myself†. I felt as though I was jumping into a sea of hungary sharks, ready to be torn apart. We spent the whole day there doing our makeup and rehearsing again and again and again. With all the hot lights and the dancing with our face and body full of makeup we started to wish we were dead. Next thing I know we were just an hour away from opening the doors. I was the most apprehensive about going through with this than I had every been. â€Å"Okay† I said to myself   Ã¢â‚¬Å"this is going to be the third time others have seen your makeup, nothing to be worried about, you didnt come here to win you came here to show off your art†. Just as I began to calm myself down the doors opened and people came flooding in. Now it was just the insecurities of me only having my mom there to support me, I really did nt expect any of my family to come. So off we go one by one we walk up on the stage as dead as we can be doing the opening number and for some reason as soon as we started all my nerves went away. This was not about me or my makeup, now this was about the show we were putting on, making sure I didnt miss my cue and maintaining my dead persona. Even when were were changing for the next category it was like I was on autopilot going through the motions without even thinking about it. After the evening gown portion we took a small intermission to get the winning results. The winner was determined not by a panel of judges but by the audience. You would place a card in the contestants box then they would tally the votes, the more people you brought the higher of a chance that you would win. I honestly did not care on my placement, how far I pushed myself out of my comfort zone and looking back having an amazing time and a story to tell, as cliche as it is, I was the winner in my book. The votes were in, they had people in   S.W.A.T team costumes to â€Å"control the zombies† we all lined up on stage when they called the two finalist. The girl who was being followed around by MTV got runner up and the women whos husband does professional makeup was the winner. I was so happy that I actually went through with this. After the show was over they wanted to interview everyone again. I unfortunately had to leave early so I wasnt able to get a full interview in bu t I was approached by the coordinator of the show. He pulled me aside and told me that because of my age they were not able to award me with my actual placement of runner up. (the prize for the winners was to travel to a convention and get the word out on the pageant, you needed to be 18 or older to go). In that moment I was the most proud of myself that I have ever been. Being publicly placed at third to find out I actually got second place to a women who had gotten her makeup done professionally, beating the other girl who had also gotten professional help and only having my mom there to vote and support me. I was in complete and total awe, I was completely speechless. Constantly wanting to give up because I didnt think I was good enough based on my experience, skill and age and not letting my fears and insecurities to drag me down. I feel that I accomplished a lot and I know for a fact that it was a major stepping stone for who I am now and what I can accomplish in the future.

Express Quantity in English for Beginning Speakers

Express Quantity in English for Beginning Speakers There are many phrases used to express quantities and amounts in English. In general, much and many are the  standard quantifiers  used to express  large quantities. Which expression you use will often depend on whether the noun is countable or uncountable, and whether the sentence is negative or positive. While much and many are among the most common, the following expressions are often used in place of much and many, especially in positive sentences: A lot ofLots ofPlenty ofA great deal ofA large number of These expressions can are combined with of in the sense of most, many, or much. A lot of people enjoy listening to jazz. A great deal of time is spent understanding these issues. But note that much, most, and many do not take of. Most people enjoy listening to some type of music. Not: Most of  people... Much time is spent understanding math. Not: Much of time is spent ... Much Much is used with uncountable nouns: There is much interest in learning English around the world. How much money do you have? There isnt much butter left in the refrigerator. Much is used in negative sentences and questions, too: How much money do you have? There isnt much rice left. Note that much is rarely used in the positive form. English speakers generally use a lot of or lots of  with uncountable  nouns. We have a lot of time. Not: We have much time. There is a lot of wine in the bottle. Not: There is much wine in the bottle. Many Many is used with countable nouns: How many people came to the party? There arent many apples on the table. Note that many is used in the positive form, unlike much:   Andrew has a lot of friends / Andrew has many friends. A lot of my friends live in New York / Many of my friends live in New York. A Lot of / Lots of /  Plenty  Of A lot of and lots of can be used with both countable and uncountable nouns. A lot of and lots of are used in positive sentences: There is a lot of water in that jar. Hes got lots of friends in London. Note that generally speaking, lots of sounds less formal than a lot of.   A Little / A Few A little and a few  indicate a quantity or number. Use a little with uncountable nouns: There is a little wine in that bottle.   There is a little sugar in my coffee. Use a few with countable nouns. He has a few friends in New York. We bought a few sandwiches on our way to the park. Little / Few Little and few indicate a limited quantity. Use little with uncountable nouns: I have little money to spend. She found little time for work. Use few with countable nouns: He has few students in his class.   Jack finds few reasons to stay. Some Use some in positive sentences when there is neither a lot nor a little. Some can be used with both countable and uncountable nouns. We have some friends who work in Los Angeles.   Ive saved some money to spend on vacation this summer.   Any (Questions) Use any in questions to ask if someone has something. Any can be used with both countable and uncountable nouns: Do you have any friends in San Francisco? Is there any pasta left?   Note that when offering or requesting something use some instead of any  for polite questions. Would you like some shrimp? (offer) Would you lend me some money? (request) Any (Negative Sentences) Use any with countable and uncountable nouns in negative sentences to state that something doesnt exist. We wont have any time for shopping today. They didnt have any problems finding our house.   Enough Use enough  with countable and uncountable nouns to state that you are satisfied with the amount of something. She has enough time to visit her friends in Dallas. I think we have enough hamburgers for tomorrows grill.   Not Enough Use not enough when you are not satisfied with the amount of something. Im afraid theres not enough time to continue this conversation. There are not enough people working at the moment.   Each / Every Use each or every when referring to the individuals in a group. I think every person in this room would agree with me. Im sure each step of this process is important.   Large / Big / Vast / Huge Amount of Use these adjectives with amount of with uncountable and countable nouns to express large quantities. This form is often used to exaggerate just how much there is. There is a huge amount of work to be done to today. Tom has a vast amount of knowledge about the subject.   Tiny / Small / Minuscule Amount of   Use these similar adjectives with amount of to express very small quantities. This form is often used in exaggeration to express how little there is of something.   Peter has a small amount of patience, so dont joke around with him. There is a minuscule amount of time left to register. Hurry up!

The islm model-finance Essay Example | Topics and Well Written Essays - 1750 words

The islm model-finance - Essay Example In the article Sir John constructed a diagram and a system of equations that represent the goods market and money market equilibrium conditions. Eventually this IS-LM model has become a famous framework for teaching, policy analysis and econometric modelling for both closed and open economies (Dimand 324). Mishkin points out that Keynes considers the total quantity demanded of an economy’s output (or aggregate output that is equivalent aggregate income) is the sum of four types of spending: (1) Consumer expenditure (C) – the total demand for consumer goods and services; (2) Planned investment spending (I) – the total planned spending by businesses on new physical capital (machines, computers, raw materials, factories, etc.); (3) Government spending (G) – the spending by all levels of government on goods and services (government workers, red tape, aircraft carriers, etc.); (4) Net exports (NX) – the net foreign spending on domestic goods and services, equal to exports minus imports (536). Aggregate demand (Yad), according to Keynes, is: Yad = C + I + G + NX and when the total quantity of output supplied (aggregate output produced) Y equals quantity of output demanded Yad: Y = Yad, so it is possible to say that equilibrium occurs in the economy (Mishki n 537). So, the Keynesian framework enables economists to analyse how aggregate output depends on changes in its constituents: autonomous consumer expenditure, planned investment spending, government spending, net exports and taxes as well. Hicks suggested his interpretation of the Keynesian model, taking into consideration three aggregate markets (money, capital and goods) (156). Hicks asserted that â€Å"in the short period the market of labour as well as price changes do not play a significant â€Å"active† role, so the model can be introduced as follows (Vercelli 4-5): where L is the aggregate demand for money (equal to

Education and Medicines in Saudi Arabia and the United States Research Paper

Education and Medicines in Saudi Arabia and the United States - Research Paper Example In spite of having various similarities, Saudi Arabia and USA are acutely diverse in various fields. In the field of education, the two countries have a completely different outlook in terms of approach towards education, the rate of literacy, religion followed in school (). Other educational differences include the gender roles, grading scales and stages of education (Stevenson). For instance, attendance is mandatory for primary and secondary level students in the USA, whereas attendance is not mandatory in similar levels in Saudi Arabia (Stevenson). Also, while the USA boasts of a literacy rate of almost 99% for both men and women, Saudi Arabia holds a literacy rate of only 84.7% for men and 70.8% for women (Stevenson). Moreover, the two countries differ grossly in terms of religion followed. Although the majority of the US population follows Christianity, the country is home to the followers of various diverse religions as well. However, Saudi Arabia is a country that strictly fol lows Islam and Muslims dominate society. Also, the two countries exhibit totally uncommon lifestyles (â€Å"The Differences†). People have a conservative mindset in terms of women. Here two women are forbidden to go outside together. Moreover, they have to keep their heads covered in public. On the other hand, USA reveals a liberal and democratic mindset in which both the genders can enjoy equal privileges (â€Å"The Differences†). Strangely, the countries, Saudi Arabia and the United States reveal both similarities and dissimilarities.

Four Theoretical Approaches to Metaphysics Essay Example for Free

Four Theoretical Approaches to Metaphysics Essay There are four theoretical approaches to the metaphysics and they include Dualism and the theory that what exists on can do so on two levels the physical or the mental. The next approach is Materialism which theorizes that everything exists on a physical level. Then there is the Idealism approach which states that everything that exists is mental or spiritual. Finally, there is Alternative Views which theorizes that what exists in neither mental nor spiritual but believed that what exists is both, which means that what exists is neutral. In the Materialism theory of metaphysics it is said that everything is made of some kind of structure that are now called atoms. These atoms are governed entirely by physical laws and are thought to make up everything that we know and see. There were and are still many men in the scientific community that feel this way, but the most pronounced one was named Thomas Hobbes. Hobbes implied â€Å"clearly that all things are made of material particles and that all change reduces to motion. † (cite) His theory states that everything is matter in motion to include an individual’s thought process. Hobbes goes into detail about how this process works and called it perception or sense. His way of describing it is the fact that things have different properties and that the properties do not really exist. The properties of an object are based on what we perceive them to be. We perceive a rose to be beautiful, smell nice, and have red pedals. Those properties according to Hobbes are all based on perception and the rose does not actually have any of these traits. â€Å"The things that really are in the world outside us are those motions by which these seemings are caused. † (cite) Hobbes describes perception as motion from the outside effects the motion of the inside of a person. The motion on the outside affected the motion on the inside and leaves a lasting effect after the motion is complete or dispersed then the motion that remains behind on the inside is left as a memory. The motion that is still on the inside is a perception and in turn is the root cause for thinking, imagination, and memory. As humans we describe this reaction by assigning words to these perceptions and Hobbes labeled that as reasoning. The way that people reason is nothing sort of â€Å"adding and subtracting of the consequences of general names. † (cite) The easiest way that this can be explained would be to refer it to a computer. The hard drive is considered as the movement on the inside and the keyboard and mouse as the outside. The hard drive is made up of a disk and magnet and works by taking the disc and spinning is around at a rapid pace. Next the magnet is moved around to encode the data to the hard drive. This whole process is done through movement and if stationary there is nothing that can be done to retrieve or store information. First to store or retrieve information an external source of movement needs to happen. Movement from the outside was represented as a keyboard and mouse. The keyboard and mouse which is movement from the outside affects the hard drive which is the movement from the inside and vice versa. Now that movement has been represented the reasoning of information needs to be considered. Now we understand what movement effect movement means we can now address the fact of reasoning and perception. All of the information that the computer takes in needs to go somewhere and needs to be retrieved again. The computer makes sense of all the data by assigning numbers to all of the data so that it can be retrieved again. This aspect would be considered our perception which is reasoning which as Hobbes stated before is our thinking, memory, and imagination. Now some people would argue that Hobbes theory does not take into accounts decision making and other voluntary actions, but he does go into detail about how that process works. Hobbes addresses the finer points of the decision process by stating that every decision or movement starts of as an â€Å"endeavor† which was caused by perception. He then breaks it down even into two groups consisting of desire and aversion. When the endeavor is toward something then it is considered a desire and when it is away it is considered an aversion. We associate desire and aversion with words like love and hate or good and bad. So according to Hobbes the basic principle of our decision making is like a magnet. Let’s look at the magnet that is in the computer and affects the hard drive. Sometimes data can be corrupted and the information will not take to the hard drive. The process of corrupt data being entered from the outside can be considered as an aversion. Now any information that the system lets in can be considers as desire. If that did not make sense then lets look at a magnet in general. A magnet has a positive and a negative side. Anything that is attracted to the positive side can be considered a desire and anything that is repelled by the negative side can be considered an aversion. In the recent years there has been some advancements in technology that allows us to uncover the mysteries of the universe. Scientists have found matter that is smaller than atoms and they are calling them subatomic particles. It has been discovered that these particles make up every aspect of the universe and are comprised of some type of energy that is connected with everything else. After this discovery a lot of scientists are rattled about their theory and if Materialism is really the right type of metaphysical theory to go with. However, this does not completely rule this theory out it just seems like that needs to some changes or tweaks to the way that we think about Materialism.

Essay --

Experiencing a poor social upbringing has influenced my desire to help children from socially deprived backgrounds achieve a success. With the drive to assist others and inspired by my mother in the teaching profession my aspirations of becoming a teacher can be recognised from the past three years of my life through my academic knowledge and experience. I am strong and varied communicator, with the belief that motivating individuals is the key to success, which gives me the confidence to adjust my approach to suit my audience. This was highly beneficial as an activities instructor as I was working with children from a range backgrounds and abilities. I demonstrated that I have valuable leadership skills as I was conducting over forty activities with a group of sixteen children. As I was sent to different camp sites in the UK I was leading different groups consistently. This increased my knowledge in the field of SEN as I was working with children with autism. I have learnt to improve children's self-esteem through motivation, praise and team innovation. As a teaching assistant/ment...