Advance managerial accounting Report Essay Example | Topics and Well Written Essays - 500 words

Advance managerial accounting Report - Essay Example This implies that data turns into information for purposes of making decisions. In the same way, Ferrara’s article â€Å"21st Century Paradigm,† the focus is on cost especially concerning industrial engineering. When Ferrara says that the volume of activity is still a problem as fixed costs grow depending on variable costs, the main point is that profitability is dependent costs. Just like Drucker, Ferrara proposes that costs affect the number of products. This is what he refers to as activity costing. In the two articles, authors clearly bring out the issue of marginal changes ignoring the impact of accounting. Data, therefore, is imperative in the two cases for continuous improvement like cutting down on the selling over a period. At the final stage, Drucker and Ferrara establish that information is crucial in any accounting system, whereby it should deal with the two issues of assigning costs between and within product lines. The next articles as well focus on utilizing costs to make decisions. Cooper and Kaplan, for instance, examine how important products are critical in controlling the costs within the market. They, at first, agree with Ferrara that costs are becoming less variable. This implies that they are the dependent factors transferring products to be independent. Cooper and Kaplan reveal that most costs change depending on the shift and diversity of products within the economy as opposed to the number of products produced (Kaplan and Atkinson 2). With reference to what Drucker tries to bring to surface on accounting systems and information, Cooper and Kaplan tend to agree with him that conventional accounting systems make more products appear more expensive than they really are. The clearest point that brings all the articles together is that management decisions vary depending on the number of product complexity as opposed to the amount. Cooper and Kaplan as well

Different Cultures Essay Example | Topics and Well Written Essays - 1250 words

Different Cultures - Essay Example Maya were never ambitious empire builders, but peaceful people who lived in harmony with nature. Roma are nomads originally lived in North West India, migrated to Persia, Middle East, and then to Constantinople to end in Western Europe and tiny population to US and Canada the last caused by World War II and Communism. Domari, Lomarvren and Romani like clans belong to this origin. This tribe was persecuted by Christians, Germans, were killed as witches, sometimes with legal and royal sanctions, were enslaved in Europe and if ever there was a population which was relentlessly hunted, tortured, systematically exterminated, they were the unfortunate Roma. Hitler went for 'getting rid of Gypsy plague' and Roma were part of holocaust and survivors did not get any support from Allies. They were the common targets of all, and should be appreciated for managing to survive, despite the murderous setbacks. They are still targeted by groups of insanity and governments have not done enough for them in any country. Maya's royalties cemented the kinship and the divine lineage by marrying ruling class members of other cities. Roma married young; courtships were allowed to some extent, but not more. Arranged, practical and sometimes love marriages were practiced, and marriages were a gala three day affair, after which, they lived with groom's parents, and only after they had children, they might be allowed to live a semi-detached life. Daughter in law is kept strictly under control and have to perform all her duties without anything in return. "The daughter-in-law must prove herself to her new family and is expected to perform services with little in return. She is expected to care for her in-laws and produce grandchildren. With the birth of her first child the daughter-in-law moves from the child or bori status to mother-of-the-child status" http://www3.baylor.edu/Charles_Kemp/gypsy_health.htm Maya did not have such rigidities, and marriages did not endanger women folk into slavery. Maya men were responsible for all outside work, earning and decision making. Women were home-bound, but not obsessively so, and took all decisions of home life and maintained a healthy economy. Aged people lived a good and sheltered life in family, because the elders were respected and cherished and here, they are close to Roma, where the house elders only could speak to outsiders and were never interrupted or advised or overruled. Both clans had gender regulated rules where women had to look after home and hearth and men, earning and external responsibilities. But Maya women definitely were more independent than Roma. Maya had rigid class system, but Roma did not have much of it, as all are equal and they were never ruled by kings, but only by a clan headman. Roma consider pregnancy and child birth unclean and keep the event out of familia home. Child is mainly mother's responsibility and mother should maintain state of wuzho and there are varied ceremonies for the father to accept the child as his own. Children are the

Advantages Of Autonomous Vehicles

Advantages Of Autonomous Vehicles Autonomous cars, or cars that run without a human driver, have been in development for over the past few decades, starting from the late 70s and extending towards the present date and even beyond. During the early stages, the autonomous vehicles were slow in speed and even in reaction time. Nowadays, with technological advancement, coupled with better research knowledge and funding towards further development, product improvement has clearly been observed. From the early days of mechanical feedback systems to modern software incorporation, numerous improvements have been made. 2. Advantages of Autonomous Vehicles Finding from the World health Organization (WHO) several years ago regarding automobile accidents: Accidents expenditure in the United States reached $230 billion; with over $30 billion going into health care. Such will only increase, because the road accidents are expected to be the third largest killer worldwide by 2020. There are two possible approaches to make cars safer. Systems can be implemented to make a car accident less lethal or to prevent accidents. Also, from an energy and efficiency point of view, in general, people are not able to drive the best as well. Having computers to do the driving is going to save energy significantly. However, since vehicles are networked and with traffic flow synchronized, it is an apples-to-orange comparison. Autonomous cars wont have to tackle congestion and stop-and-go traffic, as is present today. Road travel will speed up, more predictability, and passengers will have ample space to focus on other things while travelling. The vehicles will be a lot less heavy. There will be a reduced need for designs to deal with impacts, as the heavy vehicles of today are driven by error prone humans, nor a need to be equipped with protection instruments to protect drivers (e.g. crumple zones, airbags, or even seatbelts). Further advantages of driverless vehicles, aside from the significant safety and energy benefits that would be presented with their use, will be an increase in transportation access. Aged, restricted mobility, poor, and even the language illiterate individuals can safely travel. It will be like having a chauffeur at all times. 3. Integrating technology to make an autonomous vehicle For vehicles to be made autonomous will require advanced sensors and actuators to coordinate hand in hand. Definition of sensor and actuator Sensor A device that detects or measures a physical property and records, indicates, or otherwise responds to it Actuator An actuator is a mechanism responsible for the movement or control of a machine, apparatus or system. It utilizes energy, commonly transported by air, electrical current, or fluid, and translates that into a type of motion. 3.1. Sensors in an autonomous car In an autonomous vehicle, apart from speed sensors, sensors are used for lane position tracking as well as front obstruction detection. This comes in the form of radars. If lane positioning or safety distance is not within safety parameters, the sensor will send signals to the microcontroller. From there, the microcontroller will coordinate the various actuators such as throttle, steering and brakes to enable the vehicle to stay within the parameter. Various sensors used in the mobilization operation of autonomous cars includes a radar reflective stripe system with a vision based system for lane location sensing, a radar system and a scanning laser range finding system for the detection of obstacles ahead of the autonomous car, and various assisting sensors including off-centre looking radars and one angular rate gyroscope. Figure 1 shows a sketch of an autonomous car with the various sensors, actuators and operating devices. 3.2. Actuators in an autonomous car Brake Actuators Coordinate car speed with the sensors and/or users pre-input. Used for slowing down the car when there is a need to. Steering Actuator The steering actuator is a motor controlled by the car in-built microprocessor. The microcontroller takes in signals from the various sensors to steer the car which is done by directing the motor for controlling the angle of the wheels. Throttle Actuators Used for controlling the output of the cars engine based on the sensor or users pre-input. This will increase and reduce the speed of the vehicle as well as maintain. 3.3. Current technologies, design and construction concept used to realize various sensors and actuators in an autonomous vehicle 3.3.1. Electronic Scanning Radar Electronic Scanning Radar is an inexpensive effective object-detection system that utilizes electromagnetic waves, specifically radio waves, to determine the range, direction, or speed of both mobilized and stationary objects. Radio waves or microwaves transition from the radar sensor bounces off any object in their path. The object will then return a tiny portion of the waves energy to the antenna which is normally located at the same spot as the transmitter. Radar technology has the ability to measure positions and speed vectors of multiple targets at the same time, with precise accuracy, within a short time frame. Detection and tracking algorithms are normally given in a one-box-design and some manufacturers allow space for vehicle/customer/application specific code in the radar systems. The ESR enables a wide coverage at mid-range and high-resolution long range using stand-alone radar. Wide and mid-range coverage not only enables vehicles cutting in from adjacent lanes to be detected, but also determines vehicles and pedestrians along the width of the vehicle. Long-range coverage gives accurate range and speed data, with great object discrimination that can identify as much as 64 targets in the vehicles path. The ESR also allows powerful functionality which includes the following: -adaptive cruise control -forward collision warning -brake support -headway alert 3.3.2. Brake actuator One method of braking widely used by autonomous vehicles, although also widely used in contemporary vehicles, is the disc braking system. The main components of disc brakes comprise the following: Brake pads Caliper containing a piston Rotor that is mounted to the hub The disc brake is quite similar to the brakes on a bicycle. Bicycle brakes use a caliper, which forces the brake pads against the wheel. In a disc brake, the pads forces on the rotor instead of the wheel, and with the force being transmitted hydraulically instead of a cable. Friction between each pad and the disc slows the vehicle down. A moving car contains kinetic energy and by stopping the car, the brakes are actually removing this energy. The brakes do this by converting the kinetic energy into that of heat. Therefore, in most cars, ventilation is provided for the brakes. 3.3.3. Adaptive Cruise Control Adaptive cruise control utilizes forward-looking radar with its installation located at the back of the grill of a vehicle, to identify the speed and distance of the vehicle in front of it. Adaptive cruise control is of the same principal as conventional cruise control in that it maintains the vehicle pre-set speed. However, unlike the contemporary cruise control, this implementation can automatically adjust the speed to maintain a safe distance from vehicles along the same lane. This is performed through a radar headway sensor, digital signal processor as well as a longitudinal controller. If the front vehicle slows down, or should another object get detected, the system will send a signal to the engine or braking system to slow down. Subsequently, when the road gets cleared, the system will increase the vehicle speed back to the set value. Cruise control is an example of a closed-loop control system Closed and Open Loop Explained In a closed-loop configuration, a feedback component is being sent together with the input. The difference in the input and feedback signals is sent to the controller. In response to the difference, the controller acts on the process forcing the output to change in a direction that will cause reduction in the difference of the input signal and the feedback component. A closed-loop system has the ability to regulate itself in the midst of disturbances or variations in its own characteristics. Hence, a closed-loop system has an advantage over that of an open-loop Likewise, a cruise control has an input signal of a desired velocity. This goes through any number of amplifiers in the mode of transfer functions and gains, and then, outputs a signal which the motor utilizes to modify its power. Disturbances in the system may include wind speed, bumps on the road, etc. When these obstacles affect the speed of the car, data passes through from the end of the control system in the form of velocity data to the beginning, where it makes appropriate changes to the input signals so it can then properly adjust the speed of the car. Closed loop control systems has its output compared with the desired parameter settings and the process is varied in order for the output to satisfy the requirement. The accelerator of a conventional man-driven vehicle, on the other hand, is an example for an open-loop control. This is a simple link between the gas pedal and the car engine. When stepped on, the engine propels the car, and this does not stop until you remove the input signal (Pedal stepped on with continued pressure). Should there be obstacles along the way, this will affect the speed of the vehicle so long as pedal is being stepped on to a certain particular extend. Open-loop systems provides an output according to the desired set point irrespective to the changes that occur due to certain disturbances in the process. An open-loop control system is influenced directly, and only, by an input signal, without the beneficial use of a feedback. 3.3.4. Oxygen Sensor A vehicle oxygen sensor, also known as a lambda sensor, is a small sensor installed into the exhaust system of a petrol engine for the measurement of the oxygen concentration that remains in the exhaust gas to enable an electronic control unit (ECU) to control the efficiency of the engine combustion process. In majority of all modern automobiles, including autonomous ones, these sensors are installed at the engines exhaust manifold to identify whether the mixture of air together with gasoline going into the engine is rich or lean. That means too much or too little fuel respectively. 3.3.5. CAN-bus CAN Bus is a multiplexed wiring system commonly utilized in the connection of intelligent devices such as Electronic Control Units (ECU) on vehicles, allowing data to be transferred in reliable manner at a lower cost. This also reduces the need for massive amounts of cables In a vehicle. CAN stands for Controller Area Network and it was development was by Bosch, in 1980. Majority of new vehicles utilizes this system and it is becoming more difficult to install after-market products without the use of a CAN Bus Interface. CAN bus is commonly used in autonomous vehicles. 4. Capabilities and Potentials as well as the limitation for the various telematic devices in an autonomous vehicle 4.1. Disc Brakes Today, in almost all automobiles, both conventional and autonomous, disc brakes are the most found .They are better at stopping vehicles than many other type of brakes; which is why they are still in existence since 1902. High speed vehicles need better brakes to slow them down, so most probably a disc brake would be installed. Limitation Heat retention is a common problem with disc brakes. Unfortunately, this causes brake fade. It is where the brake components have absorbed all the heat they can possibly withstand. This means they are unable to absorb more energy and thus, will not be able to slow the car further. 4.2. Cruise Control It is definitely better to be in an autonomous vehicle. This makes life for the user easier as he do not need to drive. Also, with humans in control of the vehicle, a higher tendency of error occurs. In autonomous vehicles, one of the components that make the technology possible is the cruise control. The cruise control aids in automatically controlling the speed as well as maintaining a safe distance from the car in front. This makes travelling safer. Limitation The cruise control of todays autonomous vehicles can only track the car ahead of the equipped vehicle. This means safety is only taken in reference from the front, and not from the back. In the later part of this report, we will look into the intelligent cruise control. 4.3. Radar Sensor Radar aids in making a vehicle autonomous. Current technology enables radar to accurately detect at greater distances, identify up to 64 targets and can be integrated to an autonomous vehicle to assist in many various operations such as cruise control, braking, collision warning and headway alert. Limitation: Current implementations do not permit collision avoidance when environment is obscured with smokes and dust. 4.4. CAN-bus With the huge reduction in wiring, this leads to the following:- (i) Vast reduction in production cost; which also leads to lower retail cost. (ii) Lighter weight for vehicle, thus leading to improved fuel consumption. (b) Reduced number of interconnections, which leads to improved reliability. Limitations Installation is relatively costly, and the requirement for specialised knowledge is needed for maintenance and repair of the vehicle. 5. Continued improvements for Sensors and Actuators in autonomous vehicles The first segment in this section discusses about the improvement in intelligence provided in a sensor over the years and how it has brought about major improvements. Second section will talk about the future sensors and actuators development in autonomous vehicles. 5.1.1. Increased level of intelligence provided in sensors has and explanation to why enhancing the intelligence of a typical sensor may encourage improved performance. This section discusses the details and describes the evolution of a critical sensor in the implementation of a safety critical active controller in passenger cars called ABS (Antilock Brake System). ABS works on the principle of optimizing the wheels slips (for maximizing the brake force) in the car during the event of braking. Wheel slips are defined as below: The critical task in controlling the braking wheels of the car boils down to evaluating the speed of the vehicle and hence estimating the deceleration desired and actually achieved. The difference of which triggers the actual hydraulic pressure build up in each wheel. The complex task of vehicle velocity estimation is done through using wheel speed sensors in each wheel of the car as shown below: Until the advent of active wheel speed sensors recently, global automotive industry was using the passive wheel speed sensors for calculating the wheel speeds. 5.1.1.1. Passive Sensors Passive sensors operate with a steel tone ring application. These variable reluctance sensors are used to measure speed/position of the vehicles tone ring. As the magnetic flux through the coil of the sensor is changed, so does the resulting voltage which is then measured and used to calculate wheel speed. This technology is considered outdated and is typically bypassed for active intelligent sensors. 5.1.1.2. Active Sensors (Intelligent) Standard active wheel speed sensors operate on the Hall Effect. They are able to be used with a magnetic encoder or steel tone ring application. As the magnetic flux changes (created by an internal magnet or the magnetic encoder), the hall sensor creates an output current which can be measured and converted into wheel speed. Standard WSS only measure wheel speed and do not have any additional signals for vehicle operation. A Hall element (square shaped semiconductor layer) is supplied by a permanent current (I const). Applying a magnetic field perpendicular to the current flow the electrons are deflected due to the Lorenz force. This deflection can be measured as Hall voltage, which is perpendicular to the magnetic field (B) and the current flow (I const). The Hall voltage (V Hall) is directly proportional to the external magnetic field. The magnetic field is established either by a magnetic encoder or internal sensor magnet. These active sensors offer benefits when compared to passive sensors. The dominant factors that took the stride towards active intelligent wheel speed sensors were: Weight reduction. Size reduction. Reduction in Cost but improvement in performance. Low speed detection benefits. Passive sensors had the hurdle of building enough reluctance at low vehicle speeds but with active sensors wheel speeds can be detected with changing magnetic fields at as low as ~0.1 m/sec. Direction detection. With developing ASICs and also the magnetic encoders thereby made wheel speed sensors smarter and hence has led to the advantage of vehicle motion direction detection in the sensors. It effectively has offloaded the software task of direction detection by many folds. With detection possible at such low vehicle speeds a new development of Hill Hold Controllers was triggered in the industry. 5.1.2. Intelligent sensor and the mechanism for transferring the measurement to a central data logger or processor. Example is explained in the above question. The mechanism for transferring the measurement to a processor in this case it is ABS controller is here: CAN Bus ABS Controller Pressure application on each wheel Hydraulic controller With reference to the diagram above: The data or pulses/signals from the wheel speed sensors are collected in the special ASICs designed for this purpose from there a SPI bus architecture is used to transfer it to the software layer (HSW box above). Filtering and certain algorithms regarding determination of data usability are made in the stat machine of the software layer. Usable and filtered data is further passed down to the ABS controller through the CAN bus. ABS determines the pressure targets for each wheel and hydraulic controller applies the set targets on the individual wheels for attaining the desired stopping distance of the car. 5.2 Future Development for Sensors and Actuators in autonomous vehicles 5.2.1. Brakes In the future, the hydraulic line may not ever again be needed in an automobiles braking system. In fact, in a recent study performed by Frost Sullivan, it is predicted that, after the year 2010, the automobile industry will begin to replace hydraulic-braking systems with that of brake-by-wire. The utilization of the brake-by-wire technologies like the electro-mechanical braking system and the electronic-wedge brake is predicted to be the norm for future vehicles. This method of braking uses electronic signals instead of mechanical to achieve braking power. The electro mechanical barking system or EMB will not require hydraulic lines due to the activation of the brake being done within the wheel assembly itself. Instead of utilizing calipers, this system uses a wheel brake module. The module comprises of disc brakes and an electric motor which will be the one that activates the brakes during activation. As it is, this method of braking is known as brake-by-wire. Certain automobile companies have almost already fully implemented this system into their automobiles, namely Toyota and Mercedes. However, a full brake-by-wire system has yet to come out and will only be out in the near future. 5.2.2 Radar Future implementations will be the autonomous vehicle navigation and obstacle detection sensor radar. This device, currently being tested, will assist in reducing the quantity of separated components that is required to satisfy the needs of an autonomous vehicle. The navigation and obstacle detection can be done with just one component device. If being mounted on a suitable spot on a vehicle, this all-rounder obstacles detection and navigation radar will eliminate the need for multiple contemporary radars. This will reduce the weight of the vehicle and thus, saving on fuel cost. Furthermore, future implementations will enable obstacle avoidance and prevent collision even when environment is obscured with smokes and dust. 5.2.3. Intelligent Cruise Control In cars nowadays and in autonomous vehicles, the cruise control will only strive to maintain a safe distance from the front car. Unfortunately, this does not include the back car. With this new implementation, the spacing from the back vehicle will also be taken into consideration, together with the spacing from the front vehicle. This system also works and serves especially well when lane switching is being performed. This is due to the inadequate gap tendency between the front and back vehicle. 6. Conclusion The earlier sections in this report has aimed to bring about the ideas of current technology implementations of an autonomous vehicle. As demonstrated, there are still flaws within the system. However, with the intelligence of sensors increasing constantly, it is almost sure that many of the problems faced by autonomous vehicle manufacturers will be solved in the near future.

Global Warming Essay -- Environmental Global Climate Change

Global Warming   Ã‚  Ã‚  Ã‚  Ã‚  Two issues that worry many scientists are global warming and the greenhouse effect. The greenhouse effect is a natural process that keeps the earth at temperatures that are livable. What does the greenhouse effect have to do with global warming? When humans release gases into the air, the greenhouse effect will alter the temperature of the earth. More gases in the atmosphere means the earth will start to get warmer, and the result is global warming. On the other hand, if there was no greenhouse effect, the earth would be too cold for humans to comfortably exist.   Ã‚  Ã‚  Ã‚  Ã‚  In order to talk about global warming, we must first learn what causes the greenhouse effect. The three most common greenhouse gases are water vapor, carbon dioxide, and methane. Many of the sun’s rays are absorbed by water vapor. Water vapor is a natural atmospheric gas and it accounts for â€Å"80 percent of natural greenhouse warming; the remaining 20 percent is due to other gasses that are present in very small amounts† (Murck, Skinner, and Porter 488). A greenhouse gas known as carbon dioxide is the second biggest absorber of the sun’s heat rays. Humans affect the amount of carbon dioxide in the atmosphere in many ways. Every time fossil fuels are burned, more carbon dioxide is released into the air. Car exhaust emissions also increase the amount of carbon dioxide in the air, and more carbon dioxide means more heat rays being absorbed. This will cause the earth’s temperature to warm. Another greenhouse gas is methane. â€Å"Methane absorbs infrared radiation 25 times more effectively than carbon dioxide, making it an important greenhouse gas despite its relatively low concentration† (Murck, Skinner, and Porter 490). Many studies have been performed on how methane is released into the atmosphere. Results have shown that methane is â€Å"generated by biological activity related to rice cultivation, leaks in domestic and industrial gas lines, and the digestive process of domestic livestock, especially cattle† (Murck, Skinner, and Porter 490). The Environmental Media Services Organization has found that the greenhouse effect â€Å"could drive temperatures up as much as 6 degrees by the year 2100 – an increase in heat comparable to the 10 degree warming that ended the last ice age† (Fast Facts). If a 10-degree warming was the factor that ended the last ice age, imagine what a... ...bal warming process has started, it is very hard to reverse it. Global warming temperatures grow exponentially and we will have to create an answer for global warming sooner than people think. I don’t know how to start the process of burning less fossil fuels. All I know is global warming has to be stopped if we want to keep living the way we do now. If it isn’t stopped, the problems discussed in this paper will only get bigger and bigger and the ending result will ultimately be death. Works Cited â€Å"Campaign to Stop Global Warming.† State PIRGs (public interest research groups) Working Together. Mar. 2006. 4 Oct. 2007 http://www.pirg.org/enviro/global_w/fact.html. â€Å"Fast Facts.† Environmental Media Services. 10 July 2006. 23 Oct. 2007   Ã‚  Ã‚  Ã‚  Ã‚  http://www.ems.org/climate/sub2_climate.html. Murck, Barbara W., Brian J. Skinner, and Stephen C. Porter. Environmental Geology. New York: John Wiley & Sons, 2004. 488-490. â€Å"The Planet Speaks.† The Wilson Quarterly 25.4 (Autumn 2006): 124. â€Å"To Save Lives, Give Global Warming the Same Priority As Biological Weapons, Says WWF.† WWF Global Network. 5 Nov. 1998. 27 Nov. 2006 http://www.panda.org/news/press/news.cfm?id=158.

The Climb (Miley Cyrus)

About two years ago I went on a camping trip to Colorado with youth for Christ. It’s an organization ran through my high school. We all met up at a church and got on a charter bus, that was the longest ride of my life. It was eight-teen hours. It would have been fifteen but our tire popped on the way there. We got it fixed, and kept on moving. The closer we got to the mountains weird things started to happen. Our soda cans and potato chip bags began to pop.We were so high up that the air pressure made everything explode. And the closer we got the better we could see the mountains, because from far away all the mountains looked like hills. But as we got closer you could start to see the snow at the top of them. Which was crazy to me because it was the middle of the summer, but it made me want to get there even faster. So we arrived and people from all over the United States came to camp, so there was a huge crowd of people we didn’t even know waiting to greet us.We all w alked around and got acquainted with almost everyone, then went back to our cabins to unpack and get settled in. After that we had our very first â€Å"lodge meeting†, it was held at this big hall name bear claw. We all sang songs about god and met the camp band named Attaboy. There freaking awesome! Days went by and we all got to know each other a little more. Not all of us got along but we would sure learn to. The night before at dinner they hinted that we would be doing something special, but no one could guess what.They just told us to make sure that we were in our cabins by ten o’clock and to make sure that we had gotten a lot of rest because we would need it. So the next day we woke up and everyone ate a huge breakfast. During breakfast they announced to us that we would be doing things different that day. We all needed to return to our cabins as soon as we finished eating and put on tennis shoes, sun block, to bring a lot of water. After we all did that we met a t the circle and they told us that we were climbing a mountain as a bonding experience.So they put us in groups of three with people in our cabins, but the task was for us to bond with someone that we didn’t know. We started our journey and coincidentally my group had gotten stuck behind a group of girls from Kalamazoo, Michigan. Now none of knew these girls, but I did know that one of them had given me a dirty look at lunch the day before so I wasn’t too thrilled about walking by them. We were all having a nice walk until about half way up the mountain it had gotten really steep.It was like trying to walk up a gravel wall. Everyone on my group successfully made it up, and two people form their group did but for some reason the girl who gave me a dirty look was having trouble. She just couldn’t get up there. Everyone in her group had walked up ahead so I was forced to help her. As I was standing there everything inside of me was telling me not to help her, but I had to think about what if that was me. So I couldn’t jus let her stay down there, so I helped her. We walked up the rest of the mountain together.We talked and I came to find out that she was a really nice person, and she explained to me that she wasn’t giving me a dirty look. She was actually staring at me because she thought that I was really pretty. We walked and talked and finally made it to the top of the mountain. We sat down and ate lunch together and became really close friends, we still keep in touch to this day. So I guess u could say I learned a lesson and experienced the best thing of my life, â€Å"The Climb†. Tiarra Archie Reading 104 August 26,2010

How to Write a Lab Report

How to write a lab report Let’s take as an example a free-fall experiment. You drop a small steel ball from various heights and use an electronic timer to measure how long it takes the ball to hit the ground. From this you calculate the final speed of the ball using v = 2x/t. You believe that the ball will have a constant acceleration of â€Å"g,† 9. 8 m/s2. This will be seen if you graph velocity vs. time and get a straight line with a slope of 9. 8. You end up with a table of data giving distances and fall times and a graph of v(t). Audience Before you start writing, you have to know what audience you’re writing for.You are writing for a fellow student who has not done this lab. You will assume he has about the same knowledge of physics as you do. You need to give him enough information to do the following: †¢Understand what you are trying to accomplish and how. †¢Evaluate how accurate and reliable your measurements are. †¢Evaluate the results of the experiment. †¢Reproduce the experiment himself. Format Now you have to write the report. The report will always have the same format with four sections (for physics 111 and physics 120/125) or five sections (for physics 185/280/285). Each section should be labeled exactly as shown below.A lab report should be as brief as possible without leaving out anything important. Use complete sentences and the best spelling and grammar you can. Section 1: Theory Describe the purpose of the lab. This may be one or more of three things: †¢You are trying to prove a theory. In our case we’re trying to show that the acceleration of a body in free-fall is constant. †¢You are examining a relationship. This is what you do if you don’t have a theory. For example if you measure the time it takes a pendulum to make one swing as you vary the size of the swing, but without having a theory or formula that allows you to make a prediction in advance. You are measuring a quant ity, for example the acceleration of gravity. Also give the following: †¢Describe any simplifying assumptions you are making, such as no air resistance or no friction. †¢Give the equations you are using to analyze the data. For our experiment, we are measuring distance x and time t. From kinematics we derive the equation , from which we will get a. This section will usually be brief. Section 2: Procedure You will describe three things in this section: †¢Any equipment you used to make measurements (meter sticks, stopwatches, etc. ).This is important so the reader can get an idea of how accurate your experiment is. For our experiment we used an electronic timer and a meter stick. †¢The procedures you used. Don’t go into too much detail. This section should be brief. A drawing may be useful here. †¢Any numbers you determine before starting. This could include weights, dimensions, temperature or any other fixed quantity. Here we might write that we used a steel ball about 1cm in diameter. †¢The range of any independent variables. These are quantities you select yourself. For example, for our experiment, you might say â€Å"The height ranged from 10 cm to 40 cm. Don’t put any values for the time or speed here, since these are quantities you measured experimentally: you didn’t know them in advance. Section 3: Results There are three things that are commonly found in this section: †¢The range of measured values. From our example of dropping a ball, you would list the range of times speeds you measured in this section: â€Å"The fall time ranged from 0. 14s to 0. 27s. The calculated speeds ranged from 1. 4 m/s to 3. 0 m/s. † †¢Descriptions of any trends in the data. Did the data fit a straight line, or some other kind of curve?Give the equations for any computer fit lines. If the data is supposed to be linear, use your eye to judge whether it really fits a straight line or if it curves. (Note: If the data fits a straight line and the line passes near the origin, you can say the quantities being graphed appear to be directly proportional. ) †¢Comparisons of measured values with expectations or theoretical values. For example â€Å"Our measured value for â€Å"a† was 7. 7 m/s2, compared with the book value g = 9. 8 m/s2, a 22% difference. † There shouldn’t be anything controversial in this section.Anything that involves an interpretation or speculation should go in the next section. Section 4: Conclusions If you were trying to prove something, did you? How well does your data support the theory? There are three common answers responses to these questions: If your data matched the theory, the answer is yes. This means that you results matched the expected results within the limits of uncertainty of the experiment. It means that any trends you observed were as expected. Sometimes the data does not support the theory. If this is the case, be clear about how .For example, â€Å"The data showed a direct proportion between speed and time, but the acceleration value we obtained was 22% below the theoretical value. † Finally, you may get data that supports your theory within a certain range of values but deviates from it outside this range. For example, â€Å"The graph of v vs. t was a straight line up to a speed of 250 cm/s but curved downwards for higher speeds. † If your theory is not supported by your data, you may speculate on why not. Keep in mind, though, that â€Å"human error† is usually a bad explanation unless you know specifically of something you did incorrectly that you couldn’t fix.Discuss any weaknesses in the experiment and how they might be improved. Section 5: Error Analysis (Physics 185 Only) In this section you discuss the accuracy and validity of your experiment. You will include the handout, which will be different for each set of labs. You need to list any significant sources of uncertaint y in the values you measured directly (the raw data). You need to give uncertainty values on the final results. You need to discuss how you might reduce your uncertainties or improve the experiment. For physics 120, there will be no section 5. List any significant sources of experimental uncertainty in section 4.