Physics Lab Report Centripetal Force Essay Example

Physics Lab Report Centripetal Force Paper Sketching of the set-up Theory Centripetal force F is the net force causing the centripetal acceleration of an object performing uniform circular motion. Its magnitude is given by the equation: = Mrs.. When an object is whirled in horizontal circular motion in mid-air with a piece of string (as shown in figure 1 above), the centripetal force on the object is provided by the horizontal component of tension in the string: 2 =>2 (since r = L) Procedure 1 A triple beam balance is used to find the mass of the rubber bung, the screw nuts and the wire hook respectively. The total weight of the screw nuts and the wire hook provided the tension T in the nylon thread. 2 The centripetal force apparatus is set up (Figure 2). The paper marker is used to set the length L of the nylon string between the rubber bung and the glass tube to 0. 2 m. 3 Hold the glass tube vertically and whirl the rubber bung around in a horizontal circle. Increase the speed of the rubber bung gradually until the paper marker is just below the lower end of the glass tube (Figure 3). 4 The time of 50 revolutions of the rubber bung is measured and record the exults. We will write a custom essay sample on Physics Lab Report Centripetal Force specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Physics Lab Report Centripetal Force specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Physics Lab Report Centripetal Force specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Calculate the angular velocity w of the rubber bung and the tension T in the nylon string. 5 The steps 1, 2 and 3 is repeated for several times with different lengths L (0. Mm, 0. Mm and 0. Mm) of the nylon string. The results are recorded and the mean tension T in the nylon string is calculated. 6 Compare the mean tension (2) found in circular motion and the weight of screw nuts and wire hook (MGM). Explain their difference (if any) briefly. It the two values are close to each other, it could be concluded that the equation for centripetal force is verified. We have, By y = mix + c, slope of the graph plotted The experimental value of Tension = 41. 5 x 0. 0155 = 0. 644 N, where the theoretical value of Tension = 0. 653 N It is noted that the experimental value of is slightly lower than the theoretical one due to the several sources of error made in the experiment. Percentage error = (0. 653 x Sources of error: 1 . There is friction existing between the string and the glass tube, and there is air resistance. Thus, the motion of the circulation may be affected and the measurement of angular velocity might not be accurate. Secondly, constant speed or constant angular velocity of the rubber bung may not be maintained during the whirling. Thus, the measurement of angular velocity might not be accurate. 3. The radius of the circular motion and thus the length of nylon string L cannot be kept constant throughout the circular motion because there may be a variance of the force applied to keep the paper marker on the level of glass tube. Thus, t he string and paper marker may move up and down and the accuracy of the tension T may be affected. 4. The stopwatch is controlled by human hands. Thus, the reaction time of human brain (around 0. As) may lead to inaccuracy and affect the measurement of time taken and hence the accuracy of angular velocity is affected. 5. There may be miscounting in the number of circulations, because the time for 50 revolutions is quite long and students may be distracted. The accuracy of the experimental results can be improved by the following suggestions: 1. The experiment was carried out with the range of L 0. Mm, 0. Mm, 0. Mm, 0. Mm. Further experiments can be carried out beyond this range to increase the accuracy.

Become a TA in Graduate School

Become a TA in Graduate School If you are preparing to go to graduate school, you may want to consider becoming a teaching assistant, or TA. An assistantship is a form of financial assistance provided to graduate students. They provide part-time academic employment and the school provides a stipend to the student. Teaching assistants  receive  a paid stipend and/or receive tuition remission (free tuition) in exchange for tasks they perform for a faculty member, the department, or the college. This defrays the cost of their graduate education​ but also means they are working for the college or university and have responsibilities as both a teacher and student. What Does a TA Get? The duties that a TA performs can vary according to schools, departments or what an individual professor needs.  Teaching assistantships provide aid in exchange for teaching activities, such as assisting a professor by conducting lab or study groups, preparing lectures, and grading. Some TAs may teach an entire class. Others simply assist the teacher. Most TAs put in about 20 hours per week.   While the discount or coverage of tuition is nice, a TA is a student at the same time. This means that he or she will have to maintain their own coursework load while providing TA duties. It can be a tough challenge to balance being both a teacher and a student! It can be hard for many TAs to do this, and to remain professional among students that are probably close in age, but the rewards of being a TA can be valued long after graduation. In addition to the financial perks, a TA receives the ability to interact with professors (and students) extensively. Being involved in the academic circuit provides extensive networking opportunities especially if the TA wants to eventually become an academic professional. The TA will have a valuable in for job prospects as they network with other professors. How to Become a Teaching Assistant Because  of the steep tuition discount, or complete tuition reimbursement, TA positions are coveted. Competition can be fierce in order to secure a spot as a teaching assistant. Applicants likely have to go through an extensive selection and interview process. After getting accepted as a teaching assistant, they typically undergo TA training.   If you are hoping to snag a spot as a TA, make sure you know about the application process early. This will help you develop a strong platform and application bid, and meet deadlines necessary to apply on time.   Other Ways to Defray Grad School Costs Being a TA isnt the only that grad students can also earn a tuition stipend. If you are more interested in conducting research as opposed to teaching, your university or college may offer the opportunity to become a research assistant.  Research assistantships pay students to assist a professor with his or her research, similar to the way that TAs help professors with classwork.

MRI Essay Example | Topics and Well Written Essays - 1500 words - 1

MRI - Essay Example Due to huge abundance of water in the body, hydrogen atoms are focused upon in this process. Upon applying the magnetic field, the hydrogen atoms align in the direction of the magnetic field. Next, when radio waves are added to the magnetic field, it results in the deflection of the magnetic field and resonation of the hydrogen atoms. Resonation frequency of hydrogen atoms is dependent upon the strength of the magnetic field. Upon the switching off of the radio frequency, the atoms get aligned again, generating a signal which is used to create MRI image. After giving subtle time for atoms to relax, multiple signals are produced to detect abnormalities in the tissues. (Berger, 2002) These signals are generated in the form of an image depicting significant information. (Dawson, 2008) (Blink, 2004) It has wide range of applications in evaluating blood flow in the arteries (Clinical Policy, 2001) and diagnosis of soft tissue problems such as brain tumours, multiple sclerosis, torn ligame nts, shoulder injuries and earlier stages of stroke. MRI offers multiple privileges to probe deep into soft tissues which CT scans or X-ray do not provide. Secondly, they don’t use any ionising radiations and are thus claimed safe as radio waves are found all around and do not damage the tissues. (Berger, 2002) Thirdly, MRI offers diagnosis of a specific area in the patient at various planes unlike CT scan that is limited only to one plane. (WebMD, 2009) However, there are several limitations to it such as 1) high cost of an MRI scan; 2) victims of claustrophobia are hesitant to undergo the diagnosis and condition to hold breath for long durations, 90 minutes or so, is quite uncomfortable for aged patients. (Michaelmas, 2004) Nevertheless, MRI is one of the major breakthroughs in medicine, allowing the doctors and researchers to accurately diagnose disease conditions of ailing humans. Magnetic Resonance Venography (MRV) is another technique based on nuclear magnetic resonance that is used particularly for monitoring the blood flow in veins of the body. (Vega, 2008) A detailed account of the different scenarios at which MRA and MRV are being used is discussed in a report by Clinical policy Bulletins. (Clinical Policy, 2001) The only difference between MRI and MRV is that MRV uses special computer software to generate the images. This paper will discuss the various techniques used in MRV namely Phase Contrast 3D PC MRV, Time of Flight 3D TOF MRV and Contrast enhanced (3D MRV CE) and MRI scanners in general. Phase Contrast 3D PC MRV This technique makes use of velocity induced shifts to measure blood flow. The velocity of blood flow is proportional to the phase shift, thus giving true quantification of blood flow and direction of blood flow. (Lirng, 2010) (Srichai MB, 2009) Signal intensity is encoded by velocity on the MR image, where stationary protons appear in gray colour. Blood flow in one direction is brighter as compared to the flow in the opposite direction. (Srichai MB, 2009) A significant factor called VENC factor, which is targeted to visualize arteries or veins in the region of interest. The higher the VENC factor, the arteries become more clear and vivid on the MRI image; lower VENC factor values help in visualizing veins. The direction of flow and flow velocities can be calculated using the MRI images. (Medical Physicist, n.d.) Various implications of 3D-PC have been explored in the past decade. Stoquart-ElSankari et al investigated

Project Manager Work Assignment Example | Topics and Well Written Essays - 500 words

Project Manager Work - Assignment Example On top of that, the electrical system also has to be installed in the newly constructed house before hand over to signal the end of the project. When installing a water system in the newly built house, the major considerations that ought to be taken into account include the following: connecting the water supply into the house from the main supply often provided by the municipality as well as connecting the sewer and drainage systems to the municipality source. The trenches to lay the pipes that would supply the water system ought to be strategically dug such that they do not obstruct the movement of traffic as well as people. This also helps to prevent the pipes from damage. Cast iron pipes are suitable for the water supply into the house given that they will also serve a purpose in as far as the electrical system is concerned. The electrical system is earthed on the cast iron water pipes to prevent unprecedented electrical faults that may occur within the building. These pipes are also suitable for cooling and heating of water since they can sustain extremely high temperatures as well as cold temperatures. This goes along with the HVAC system which involves things like â€Å"electrical wiring, refrigerant and combustion systems, and airflow through heating ducts which all work together to add heating or cooling comfort to a home,† (Angie’s, 2014). With regard to the drainage and sewer system, PVC pipes are suitable since they are specifically designed for that purpose. These come in different sizes and shapes and they are flexible such that they can be heated to take the desired form. The other important aspect that ought to be taken into account in this particular project is related to the installation of the electrical system. The electrical system has to be connected from the main supply and proper breakers have

Why Internet Privacy Matters to Consumer Essay Example | Topics and Well Written Essays - 500 words

Why Internet Privacy Matters to Consumer - Essay Example As Cronin points out there is billions of customer data existing on computers across the world today, including bank accounts, credit card accounts, mortgage information, retirement fund details, medical claims and much more, and 'the web seamlessly links it all together' (Cronin, 1). Search Engines are a great mine of information. Privacy concerns range from popular search engines like Google and Yahoo which track IP addresses, time of search and search details. When search history, registration details and email details are taken together, you can have a comprehensive personal profile of any user. Cronin in her essay contends that many users 'are not aware that their online behavior is so readily recorded and analyzed' (Cronin, 2). Legal bodies in many countries have addressed the privacy issues, though this has not translated to new legislation. For example, a body in Norway has stated that Google's retaining for information for 18-24 months is too long a duration. Cronin argues that 'unless there is some external pressure to place limits on how much information is collected, or how it is being used, it seems that data mining practice will be fine tuned and expanded' (Cronin, 3). E-commerce sites command personal information including credit card information and purchase history.

Crumb Rubber Particles as an Alternative Aggregate

Crumb Rubber Particles as an Alternative Aggregate EXPERIMENTAL STUDY OF CRUMB RUBBER PARTICLES AS AN ALTERNATIVE AGGREGATE IN ROLLER COMPACTED CONCRETE Abstract Several research works have been evaluated potential of the fresh concrete and hardened concrete properties of crumb rubber concrete (CRC). Technical characteristics (porosity, ductility, cracking resistance performance) can be improved by using rubber particles (Meddah et all., 2014). The aim of this present study is to elaborate the performance of different size crumb rubbers in roller compacted concrete (RCC). This study investigates experimentally the effect of using four particle size of crumb rubber (CR) (0.5-1mm, dust crumb), (1-3mm), (3-5mm), and combination of all of them in RCC by replacing with 0%, 10% aggregates 7, 14 and 28 days. Tests conducted on the fresh and hardened concrete include unit weight, toughness, modulus of elasticity, porosity, compressive strength, tensile strength are investigated respect with crumb rubber in RCC mix. Key words: Sustainability, Recycling, Concrete Technology, CR, CRC, RCC. Background Industrial and manufacturing wastes lead serious and ongoing threats in the environment. Sustainable development principles and environmental protection regulations help to conserve natural resources and reduce the amount of waste without jeopardizing the future. Therefore, recycling has been providing a significant environmental awareness related with construction. Sustainable structural engineering has become increasingly important subject for researchers.   Recycling and application of waste materials in concrete has been increasing to improve material properties of the concrete when decreasing costs of concrete in the past three decades (Ataei,2015). Relating to this principle, different environmental friendly solutions have been searched by improving material properties of the concrete. Reusing the demolished materials helps to prevent environmental pollution, keep the natural sources and use eco-friendly materials. Integrating environmental-friendly construction solutions is a highly focus field infrastructure or new construction projects by using polymer materials. Concrete additives producing from waste materials such as cellulose, wood lignin, bottom ash, fly ash and silica fume have been considered as viable or beneficial (Toutanji,1996). Rubber has attracted a great research attention because of the enormous quantities of waste rubber around the world and its potential in the construction. Many civil engineering applications have been carried out the utilization of rubber for the production materials in the construction industry. Rubber is one of the three main polymer material groups; the annual consumption of natural rubber is more than 15 million tons, and the output of rubber products is more than 31 million tons worldwide [1]. Accumulation of discarded waste tire has been a major concern because waste rubber is not easily biodegradable even after a long period of landfill treatment [2]. The storage of wastes in landfills represents environmental and public health hazards of increasingly relevant. The landfills with rubber waste are responsible for a grave risk in the ecology and the threat is always present. Even after long-period of landfill treatment, unmanaged waste tire poses environmental health risk throug h fire hazard and as a breading ground for disease carrying mosquitoes. Therefore, utilization of crumb rubber (CR) from this scrap tires for the production building materials in the construction industry would help to reserve natural resources and also maintain the ecological balance [3,4]. Crumb rubber concrete (CRC) has been previously investigated to determine the fresh and hardened properties in several research works such as waterproofing, asphalt pavement, membrane lines. Previous works show that unit weight of CRC decreases as the percentage of the CR replacement increases due to the low specific gravity of CR particles. The strengths (compressive, flexural, splitting and modulus) of CRC decrease as the partial replacement of fine aggregate with CR aggregates. CRC exhibits high capacity for absorbing plastic energy under both compression and tension loading which also possesses higher toughness. Partial replacement of the fine aggregate by CR will improve workability of CRC [5,6,7,8]. RCC is a dry (zero-slump) conventional concrete which has been made by vibrating rollers (Neville and Brooks, 1990). RCC has same ingredients with ordinary concrete (aggregates, cement, water and admixtures), lower cost and easier implementation (Meddah et all.,2014). So, RCC properties which is the subjected matter of this study is considered its advantages with CR. Aim and Objectives The main objective of this research is to improve performance of RCC by mixing with CR. Based on this research, five mixes are prepared RCC without CR, RCC with CR (maximum size of 1, 3, and 5) by using coarse and fine aggregate, cement, water and additive. There are 15% cement, 30% aggregate, 55 % sand. Crumb rubber is used to replace with fine aggregate (sand) at 10%. In particular, technical objectives can be described as follow. To define contents of RCC, cement and water contents are prepared related to ASTM D1557 standards (Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort) by using soil mechanics procedure (Marchand et al.,1997; Meddah et all, 2014). To understand density and workability, according to ASTM C1170 (Standard Test Method for Determining Consistency and Density of Roller-Compacted Concrete Using a Vibrating Table), mechanical tests of fresh concrete (VeBe test and density of fresh concrete) can be measured for each sample. To evaluate mechanical tests of hardened concrete (Compressive Strength Test, Splitting Tensile Strength Test and Bending Test are measured at 7, 14, 27 days related to ASTM C39, ASTM C78 and ASTM C496. Each test consists of 3 samples to each rubber contents. The arithmetic mean of three value is investigated for all experiments. Cylinder and cube specimens (150 x 300mm) and (100 x 100 x 100 mm) are prepared for compressive strength test, beam specimens (100 x 100 x 500 mm) are made for bending strength test and cylinder specimens (150 x 300 mm) are used for splitting tensile strength test. To determine static modulus of elasticity and poisons ratio of concrete in compression, ASTM C469 is used at 28 days. Number of Samples Compressive Strength Bending Strength Splitting Tensile Strength Rubber Size Cylindric (150300 mm) Cube(100x100x100mm) Prismatic(100x100x500mm) Cylindric (150 x300mm) 0 3 3 3 3 0.5-1mm 3 3 3 3 1-3mm 3 3 3 3 3-5mm 3 3 3 3 0.5-5mm 3 3 3 3 Total number of sample is 60.

Sexual Identity in Africa Essay -- Sexual Issues

A passionate subject, a cultural and universal practice, a part of the human nature and a divine attribute bestowed upon man by his creator. No culture is superior to another when it comes to sexuality, its acts is everywhere. It doesn’t change the face of any culture or change modernity from moving forward. Sexuality, sexual harassments, sexual dimorphism, sexual orientation, sexual intercourse, gays, lesbians, sexual preferences, sexual rights, sexual selection, sex appeal, being sexy, an endless list of each phrase, briefly coming with one source word; Sex. Sex has been a necessity, even though it is hardly ever discussed. In time past, in every part of the globe, there has always been a universal acknowledgements of the act â€Å"SEX†. Socially, it is an act a man and woman (wife/wives) engaged in after fulfilling the appropriate marriage rites. Politically, in ancient history and in present times, it was and still is the ultimate weapon of seduction that gave/gives most of our prominent women power over their male opponents. Over the years, sexual activities have grown to affect our lifestyles and perspectives (life views) to a great extend. In distinct parts of the world, the concept of sexual expressions and identities took diverse forms. The forms cut across beliefs, religions, perceptions, moral standard and even politics. However, certain things were settled for. According to N.M Heckel, in medieval times, â€Å"Sex was measured, as it is now, to be a normal and natural part of life. Most authorities agreed that it was not intrinsically sinful because God would not have made such a necessary activity to be a taboo (without sex one cannot have children and fulfil the commandment to "increase and multiply, and repleni... ...tisfree/cifamerica/2011/nov/02/america-problem-sex-education> Hoeksema, S. Inclusive Sex Education Needed in African Schools. 11th Nov 2011, 24th April 2012. Web. Heckel, N. Sex Society and Medeival Women. 24th April 2012. Web. http://www.lib.rochester.edu/camelot/medsex/text.htm Meston, C, Ahrold, T. Ehtnic, Gender and Acculturation influences on Sexual Behaviours. DOI 10.1007. 2008. Print. Mirrer, L. Women Jews and Muslims in the texts of Reconquest Castile. University of Michigan press. Michigan. 1996. Print. Neary, L. Homosexuality in Africa is Still a Taboo. 22nd February 2010. 26th April 2012. Web. AUN students. Personal Interview. 14-14th April 2012. Wikipedia. Premarital Sex. 24th April 2012. Web.