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Unformatted text preview: hinojosa (jlh3938) – oldmidterm5 02 – Turner – (58185) 1 This printout should have 34 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Needing help, the secretary of the United States Department of Agriculture asked your teacher, “If a chickenandahalf can lay an eggandahalf in a dayandahalf, how many days will it take three chickens to lay twenty eight eggs?” Please help your teacher select the correct answer to the secretary’s question. 1. Three chickens will lay twentyeight eggs in twenty days. 2. Three chickens will lay twentyeight eggs in sixteen days. 3. Three chickens will lay twentyeight eggs in twentytwo days. 4. Three chickens will lay twentyeight eggs in twelve days. 5. Three chickens will lay twentyeight eggs in fourteen days. correct 6. Three chickens will lay twentyeight eggs in twentyone days. 7. Three chickens will lay twentyeight eggs in fifteen days. 8. Three chickens will lay twentyeight eggs in twentyfour days. 9. Three chickens will lay twentyeight eggs in nine days. 10. Three chickens will lay twentyeight eggs in eighteen days. Explanation: Basic Concept: The information given in the question is the rate of egg production in one instance and you must make this rate compatible with another instance. The rate of egg production is constant. The number of eggs per chicken per day is a constant. Solution: Since it takes a chickenandahalf a dayandahalf to lay an eggandahalf, it will take one chicken oneandahalf days to lay one egg. Therefore, to lay twentyeight eggs it will take three chickens fourteen days. Alternative Method: Unit analysis is basic to every physics problem and is central to this problem. The rate of egg production is the number of eggs produced per chicken per day. In the given instance the rate is rate = { 3 / 2 eggs } { 3 / 2 chickens } { 3 / 2 days } = 2 3 eggs chickens · days . (1) In the requested instance, the number of chickens is (3 chickens) and the number of eggs is (28 eggs). The number of days N is to be determined. Therefore in the requested instance, the rate is rate = { 28 eggs } { 3 chickens } {N} . (2) The rate is constant, so equating the rates Eqs. (1) and (2), we have 2 eggs 3 chicken · days = 28 eggs 3 chickens · N Solving for the number of days N , we have N = 28 eggs 3 chickens 3 chickens · days 2 eggs = 14 days . The correct answer: “Three chickens will lay twentyeight eggs in fourteen days.” Note: The early chicken catches the worm. 002 10.0 points A weight (with a mass of 26 kg) is suspended hinojosa (jlh3938) – oldmidterm5 02 – Turner – (58185) 2 from a point near the righthand upper end of a uniform boom whose mass is 15 kg . To support this boom, a cable runs from this same point on the boom to a point on the wall (the lefthand vertical coordinate at a height of 10 m) and by a pivot (at the origin of the coordinate axes) on the same wall.coordinate axes) on the same wall....
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This note was uploaded on 07/07/2010 for the course PHY 302 taught by Professor Staff during the Summer '08 term at University of Texas.
 Summer '08
 Staff

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