Polygon of Forces and Condition of Equilibrium

Polygon of Forces and Condition of Equilibrium Introduction The polygon of forces represent lot of forces leading in a simultaneously to one point so all this forces acting will make a figure or they are call Vector such as force, that has magnitude and direction and can be resolved into components that are odd functions of the coordinates. A vector is a directed at an angle to the horizontal (or the vertical) can be thought of as having two parts (or components). That is, any vector directed in two dimensions can be thought of as having two components. For example, if a chain pulls upward at an angle on the collar of a dog, then there is a tension force directed in two dimensions. This tension force has two components: an upward component and a rightward component. As another example, consider an airplane, which is displaced northwest from OHare International Airport (in Chicago) to a destination in Canada. The displacement vector of the plane is in two dimensions (northwest). Thus, this displacement vector has two components: a northward component and a westward component. http://www.physics247.com/physics-homework-help/dynamics8.jpg Newton law variety of ways by which motion can be describedwords, graphs, diagrams, in this unit Newtons Laws of Motion the ways in which motion can be explained will be discussed. Isaac Newton a 17th century scientist put forth a variety of laws, which explain why move objects or dont move as they do. These three laws have become known as Newtons three laws of motion. The focus of Lesson 1 is Newtons first law of motion. http://www.physics247.com/physics-homework-help/dynamics8.jpg Method Attaching four lengths of strings to the pulley of fine cord and adjusting the weight of F1: 850g F2: 800g F3: 800g F4: 800g to the maximums to the string and them put a sheet of paper record all the line on the sheet of paper to help you to do all the calculation did this experiment. Results The values was in grams so this values as to be convert to Newtown so to convert kilogram to Newtown you multiply by the value in kilogram by 9.81 My value are F1: 850g = 0.85kg  ´ 9.81 = 8.34N F2: 800g=0.80kg ´ 9.81 =7.85N F3: 800g=0.80kg ´ 9.81 =7.85N F4: 800g=0.80kg ´ 9.81 =7.85N X axes Y axes F1= 8.34N cos 42 °= 6.20N F1= 8.34N sin 42 °= 5.58N F2= 7.85N cos 136 °= -5.65N F2= 7.85N sin 136 °= 5.45N F3= 7.85N cos 224 °=-5.65N F3=7.85N sin 224 °= -5.45N F4= 7.85N cos 313 °=5.35N F4=7.84N sin 313 °= -5.74N SFx= 0.25N SFy= -0.16N R = 0.192N angle q =20 ° Discussion This results are equilibrium but they was same human error thats why the results are not equal to zero but it ok so the percentage error of are 0.41%. These lines of action produce a closed polygon thats why a drawing of polygon of forces as been draw from head to tail to prove that the result of this equation and the drawing as a result angle of 20 °. The analytic of forces show that these forces are equilibrium but the result shows that there is an error in the calculation this error is duo to loose of fiction, this can happen by the loop move or human error. The possibility of losses friction experiment are the pulleys when it running can cause losses of friction, the cable was use in this experiment could be one of problem is well and another possibility is that the person ho transfer the line in to the sheet of paper did not mark the follow the line. Looking to this experiment the difference between static friction and kinetic friction is that static friction when it applied force is less than the limiting friction, the body remains at rest It is the friction experienced by a body, when it is at rest, or when the car is at full stop or not moving. Kinetic friction When it applied force exceeds the limiting friction the body starts moving over the other body and the Friction of resistance experienced by the body while moving and if you are running for you to stop kinetic friction will apply. FRICTION Frictions can benefits to our life because friction it happen to Olmos every think we do in our daily life, exp: when pushing a baby pushchair these friction there, when we slip friction is there, when we shaking hands friction is there to and it important uses in some situations, friction is very important and beneficial. There are many things that you could not do without the force of friction. Friction and weight are common experiences and taken for granted, but were not always understood. Aristotle believed that objects that contained earth fell because in Earth was at the center of the universe, and that was the natural order of things. We know that weight, which is the force of gravity between objects, not only makes apples fall from trees, but keeps the Moon circling the Earth, and the Earth circling the sun. Aristotle also believed (and some students still believe) that the natural state of an object is to be at rest. That is, without a force pushing it, an object will slow d own to a stop. This view overlooks friction, which is the force that causes most objects we see to come to rest. Now we know that there is nothing pushing planets along their orbit, and that without gravity to hold them in orbit, they would continue to move in a straight line until interfered with Friction. The disadvantage of friction is that you could not walk without the friction between your shoes and the ground as you try to step forward; you push your foot backward Friction holds your shoe to the ground, allowing you to walk Consider how difficult it is to walk on slippery ice, where there is little friction when you playing a football match it makes friction and friction also cause as to use lot of energy so we are playing a big object on friction Writing with a pencil requires friction You could not hold a pencil in your hand without friction It would slip out when you tried to hold it to write The graphite pencil led would not make a mark on the paper without friction. A pencil eraser uses friction to rub off mistakes written in pencil lead Rubbing the eraser on the lead wears out the eraser due to friction, while the particles worn off gather up the pencil lead from the paper. The means of reducing friction when moving a large object is that if two people move the object with the same forces they will be less friction and you need to reduce friction between the box and the tile floor so that you can move the box easy, you can increase friction on your shoes to help you move the box. Static friction Static friction is friction between two solid objects that are not moving relative to each other. For example, static friction can prevent an object from sliding down a sloped surface. The coefficient of static friction, typically denoted as ÃŽ ¼s, is usually higher than the coefficient of kinetic friction. Kinetic friction Kinetic friction occurs when two objects are moving relative to each other and rubs together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as ÃŽ ¼k, and is usually less than the coefficient of static friction for the same materials. In fact, Richard Feynman reports, with dry metals it is very hard to show any difference. Finally, new models are beginning to show how kinetic friction can be greater than static friction.A surface can always supply a normal force, perpendicular to the surface. However, a surface quite often also supplies a fiction force parallel to the plane. Friction forces always oppose the motion or prevent the motion. Conclusions Friction is necessary in many ways to prevent slipping or sliding but also, it can be a nuisance because it can affect many thinks in our life by in reality friction is very important, in this report the very important key is that the experiment went well as according to plan the calculation was correct but the was a small error in the all project that we count prove that this equation was equilibrium but the error did came from many ways exp: human error and many thinks. References http://www.physics247.com/physics-homework-help/dynamics8.jpg http://en.wikipedia.org/wiki/Static_friction

Violent Tv Programs

violent tv programs have been blamed for causing crime rates to rise in many countries. but many people dont agree that violence is related to TV viewing. Discuss the possible reasons for both opinions. give your opinion as to wether or not violent programs should be taken off the air. It has long been asserted that watching crime on television or playing violent video games contributes to violent behavior. In other words, it is what a person watches that allegedly influences and desensitizes him. Thus he becomes violent. Consider the absurdity of such a thesis! . People who are fascinated and excited by violence and other crimes gravitate to particular types of programs and games and immerse themselves in them, some for hours each day. Their absorption with violence reflects their personality. 2. Millions of people view violence in television programming†¦ It is entertainment or news. That's it! The viewers do not consider for a moment enacting what they see. The same is true w ith playing video games. They are solely for recreation. 3. There is such a thing as a â€Å"copycat† crime.A person watches a crime enacted in detail on television and then does the same thing. His decision to do so reflects a mind that has long been fascinated and excited by crime and violence. For every person who might fantasize about, then replicate the crime, millions of people who saw the very same thing reject it, are repulsed by it, and never would be tempted to enact what they watched. Related Articles Massacre for the Media One-Way Trip to Davy Jones' Locker Porn For Pedophiles: ‘Sexy Children' On Parade â€Å"Forced† to Kill You FirstCasey Anthony Is Found Not Guilty Of Killing Her Daughter Find a Therapist Search for a mental health professional near you. Critical is not what is on the screen or in the game but what already resides in the mind of the viewer, reader, game player, or listener. A â€Å"not guilty by reason of television† defense failed many years ago in a Florida courtroom. Violent tendencies reside within the personality, whether or not the person watches programming depicting violence. The television program, the movie, or the videogame do not turn him into something alien to his basic personality.

Edocs, Inc. †Case questions

3. The most important terms for edocs founder Kevin Laracey to further discuss in future negotiations will be the following: †¢ The valuation proposed by the Venture Capital investors, a number that could easily be inflated by shopping the deal around as the venture capital market is booming. †¢ The Board of Directors provision, as Mr. Laracey wants to make sure that in the first years of the Company he will remain CEO, and that the co-founders of edocs will be part of it as well. †¢ The share vesting schedule, which Mr. Laracey feels represents a lack of faith by the Venture Capital Investors in them. †¢ The Anti-dilution and Right of First Refusal which in essence binds edocs to future and larger equity participations from CRV. †¢ The warrants issue subject to the availability of other VC investors. This clause is troublemsome for the CEO of edocs because it will cause further dilution of his his colleagues stakes in the Company. 4. As for Charles River Ven tures, Mr. Guerster has essentially two main things in mind regarding the term sheet: †¢ The board composition, because he feels that Mr. Canekeratne is not suitable to be a board member as he will bring no added value to the company, and a large board of directors is not feasible. †¢ The warrants issue that Mr. Guerster feels is an appropriate penalty for edocs if they cannot find other investors to do the deal with. 5. edocs is searching for venture capital financing in 1998, a vibrant year for the market. Furthermore, the term sheet that was presented to them was quite investor friendly, with some strict provisions that unnecessarily burden the entrepreneurs. In short, edocs can and should negotiate some of the terms presented to them by CRV. First of all edocs is aware that if it shopped the deal around it could get a higher valuation and the provision to include the employee share option pool in the valuation seems too onerous. An acceptable compromise between committing to CRV and to dilute their stake so much in the beginning would be to exclude the option pool from the valuation. This would change the VC’s stake from 38% to 33%. May not seem like a respectable sum at first, but it may be relevant to encourage future financiers. The lower the A round investor’s stake, the better. Another provision that should be altered is the board composition. As it was mentioned before, this is bound to be one of the most contentious issues between the entrepreneur and the VC. The founders argue that all 3 of them should be on the steering wheel after the investment, while CRV insists on having a small board of directors with as many board representatives as the founders (2 and 2). It is likely that the founders will have to cave in on this issue because it’s not likely that they would get better terms elsewhere. Even if it is unreasonable to put the 3 founders of the company on the board, as the VC will not want it to have a founder majority, at least Mr. Laracey should be granted a place as a CEO for a fixed amount of time. In a very early stage it is important for the Company to have the guidance of someone who founded and knows the business by heart. Perhaps more importantly we have the warrants provision. There is a rational economic reasoning behind this provision. If CRV cannot find another party to invest in the Company thi s will mean two things: investors are not willing to bet on the success of edocs which sends a negative signal to CRV, and it will result in an undiversification of its portfolio and consquently more risk. CRV will consequently want a compensation for this extra risk and the warrants are apparently the answer. We have to take edocs’ position into account though. As we will see later they have negogiating leverage and as such are in a position to change the provision. On the other hand, the clause at the least creates some perverse incentives for CRV. If CRV is or turns out to be confident about the future success of edocs it will not try to look for additional investors and will just cash in the cheap warrants. As such, and to make the term sheet a little more Company favorable we believe that the side letter should not be included in it. In conclusion in a time where a large inflow of capital to VC funds is pushing valuations up, edocs has an opportunity to use that leverage to, while not explicitly shopping around the deal, eliminate the provisions that dilute their shareholdings excessively and to have some control of the Company during its first years. From the preceding discussion we can conclude that the term sheet is more investor friendly –i. e. CRV friendly- than company friendly –i. e. favorable for edocs. Therefore, in the negotiation process the venture capitalists have more to lose when the terms of the deals after negotiation, giving edocs more power in turn. Also, from Exhibit 18-8 we can tell that the commitments of venture capitalists have been increasing exponentially over the past years. From this we can conclude that there are many potential VCs out there who might very well be willing to finance edocs at more favorable terms, giving the latter again more bargaining power in the negotiation process. Laracey, Moran, and Canekeratne have done an extensive study on the competitive landscape in the electronic payment and bill presentment services market. They identified several (potential) competitors such as IBM, MSFDC, Checkfree, International Billing Services, and document services. Compared to edocs these firms are more established and are active in the market for a longer period of time, nonetheless they are all largely competing for the same clientele. In order to outperform these parties edocs builds on many different key elements. First of all it offers advantages to the billing entity in the sense that it allows them to differentiate from their competitors’ â€Å"print only† offerings. From a cost perspective, edocs allows for significant savings in terms of document delivery, processing, remittance, and printing costs. Also, the service will be beneficial for the customer who receives the bills. They can push the documents to the preferred e-mail package, and bill payment will be easier and not as time-consuming. Especially, the technological and strategic partnership with CyberCash will allow for â€Å"one-click† bill payment. The main point at which edocs differs from its competitors is that edocs is offered as a software product, whereas the competitors mainly offer Internet document production and delivery as a service. The founders figured that competitors had a hard time gaining acceptance for these service-only offerings, since customers are concerned about third parties standing in between the biller and the customer. Also, the fact that Laracey, Moran, and Canekeratne had access to cheap software development personnel in Sri Lanka allowed them to differentiate themselves from their competitors, because edocs software was now developed both more quickly and cheaper than competitors could develop the software. Edocs can also be compared to similar firms from a financial point of view. Exhibit 18-6 gives an overview of financial data of comparable firms. However, it must be noted that it is questionable to what extent these firms are all really comparable to edocs. More specifically, IBM and Xerox are much more established, mature firms. Documentum and Document Sciences are, like edocs, both young firms, because they only reveal sales data as of 1995. Checkfree is the only start-up in this context that is not making profit so when wanting to do a relative valuation, using multiples that include net income does not make much sense. Hence, in order to come up with an implied valuation for edocs, we propose to do a multiple valuation, including the average market value-to-sales multiple of comparable start-up firms as a relevant measure to compute the value of edocs. Appendix A gives an overview as to how we came up with this number. As said before, we disregarded the data from IBM and Xerox because these firms are in a much more mature phase than edocs. Subsequently, we computed the average MV-to-sales multiple for Documentum, Document Sciences and Checkfree over the period of 1994 to 1997. Next, this number was multiplied with each of the sales forecasts under the â€Å"target performance scenario†(retrieved from Exhibit 18-4). Averaging the value of the period between 1998 and 2002 leaves us then with an implied value of $268. 3 million.

Can You Remove Fluoride By Boiling Water

Some people want fluoride in their drinking water, while others seek to remove it. One of the most common questions in chemistry relating to fluoride removal is whether you can boil fluoride out of your water. The answer is no. If you boil water or leave it on a hot plate for an extended period of time, the fluoride will become more concentrated, remaining in the water as a fluorine salt. The reason is that youre not trying to boil out elemental fluorine, which is F2, but fluoride, F-, which is the ion. The boiling point of the fluoride compound — 19.5 C for HF and  1,695 C for NaF — doesnt apply because youre not dealing with the intact compound.  Trying to boil out fluoride is akin to boiling out sodium or chloride from dissolved salt in water — it wont work. Boiling to Distill Water to Remove Fluoride However, you can boil water to remove fluoride if you capture the water that is evaporated and then condense it (distill it). The water you collect will contain much less fluoride than your starting water. As an example, when you boil a pot of water on the stove, the fluoride concentration in the water in the pot increases. The water that escapes as steam contains much less fluoride. Methods That Remove Fluoride From Water There are effective methods to remove fluoride from water or lower its concentration, including: Distillation: boiling the water, collecting the vapor, and chilling the vapor until it forms liquid waterReverse osmosis: forcing water through a semipermeable membrane, leaving the fluoride and other ions on one side of the membrane, with higher purity water on the other side.Activated alumina: running water across activated alumina (aluminum oxide), which captures the fluoride so the water has a lower ion concentration. Methods That Do Not Remove Fluoride These methods do not remove fluoride from water: As mentioned, normal boiling does not remove fluoride. It increases its concentration.Most water filters dont touch fluoride.Freezing water doesnt remove fluoride. Fluoride lowers the freezing point of water (freezing point depression), so ice from fluoridated water will be higher purity than the source water, providing some liquid remains. Similarly, icebergs are freshwater rather than saltwater. The fluoride ion concentration is low, so using freezing to purify water is impractical. If you freeze a tray of fluoridated water into ice, the ice will have the same fluoride concentration as the water. Fluoride concentration is increased after exposure to nonstick cookware. Nonstick coating is a fluorine compound, which leaches slightly into water and foods.