Planning In this piece of coursework‚ I am going to investigate what affects the resistance of a piece of wire. Wire is made up of atoms. Electric current is a flow of electrons‚ and it is these electrons that collide with the nucleus of the atoms. Every time this happens‚ it causes resistance. The build up of friction is what produces the heat. There are many variables that could affect the resistance of the piece of wire: Length Potential difference Tension Temperature Diameter
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to find the resistance of a piece if wire. The piece of wire is my dependent variable throughout the investigation. I changed the length of the wire in order to measure the resistance of each length. Plan In this investigation‚ a simple circuit will be set up to read the voltage and current when the length of the wire changes. The length will range from 10cm-80cm with intervals of 10cm. The length of the wire will be changed by moving the crocodile clip across the wire and checking the measurements
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Sampling and Sampling Methods There are many research questions we would like to answer that involve populations that are too large to consider learning about every member of the population. How have wages of European workers changed over the past ten years? Questions such as this are important in understanding the world around us‚ yet it would be impractical‚ if not impossible‚ to measure the wages of all European workers. Generally‚ in answering such questions‚ social scientists examine a fraction
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Film: The wire (TV series 2002-2008) The series features the abuse of narcotics from a law enforcer’s‚ abuser’s and a drug dealer’s perspective. Rational choice theory This theory settles on a practical belief that man is an actor who reasons contemplates on benefits‚ means‚ costs and ends then makes a rational choice. Man has a sense comprehensible rationale of free will‚ where he evaluates the risks and benefits for committing a crime. From the excerpts from the film (season1)‚ we see a night
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Purposive sampling Purposive sampling‚ also known as judgmental‚ selective or subjective sampling‚ is a type of non-probability sampling technique. Non-probability sampling focuses on sampling techniques where the units that are investigated are based on the judgement of the researcher. Purposive sampling explained Purposive sampling represents a group of different non-probability sampling techniques. Also known as judgmental‚ selectiveor subjective sampling‚ purposive sampling relies on
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FACTORSBranding: Should the name of the product on the package and in advertising be "Colgate Precision" or as "Precision by Colgate"Communication and promotion: This is an effective way to pull a market share because it is hard to increase primary demand unless stealing sales from existing productsMajor competitors in the super-premium segment: Oral-B‚ Reach Advance Design‚ Crest Complete‚ and Aquafresh FlexDifferential pricing structure: Niche market vs. Mainstream marketDifferent advantages/ disadvantages:
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Evaluation Professor: Dr. Elidio T. Acibar Reporter: Evelyn L. Embate Topic: Sampling SAMPLING Measuring a small portion of something and then making a general statement about the whole thing. Advantages of sampling Sampling makes possible the study of a large‚ heterogeneous population It is almost impossible to reach the whole population to be studied. Thus‚ sampling makes possible this kind of study because in sampling only a small portion of the population may be involved in the study‚ enabling
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Sampling is the use of a subset of the population to represent the whole population. Probability sampling‚ or random sampling‚ is a sampling technique in which the probability of getting any particular sample may be calculated. Nonprobability sampling does not meet this criterion and should be used with caution. Nonprobability sampling techniques cannot be used to infer from the sample to the general population. The advantage of nonprobability sampling is its lower cost compared to probability sampling
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Accuracy and Precision Laura Norwood CHM/110 October 11‚ 2012 Dr. Grant W.Wangila Accuracy and Precision Chemistry is a vibrant part of society. When experiencing some of life’s simplest of pleasures‚ there is usually a process that has undergone different aspects of what a chemist studies every day. In the text for this course‚ the example of experiencing even a simple sunset can be related to chemistry. “Molecules in the air interact with light from the sun‚ scattering away the blue
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Copyright 2010 Graham Elliott. All Rights Reserved. Sampling We are now putting all of the pieces together. Considering each observation xi as an outcome from a random variable Xi ‚ we have that functions g(x1 ; x2 ; :::; xn ) are draws from the random variable Pn g(X1 ; X2 ; :::; Xn ): For 120a the function we are interested in is the sample mean — g(x1 ; x2 ; :::; xn ) = n1 i=1 xi : In this chapter we work with this function for distributions with many random variables. 1 From the Text Question
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