ebook img

Introduction to Agricultural Engineering Technology: A Problem Solving Approach PDF

395 Pages·2007·6.83 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview Introduction to Agricultural Engineering Technology: A Problem Solving Approach

P1:OTE/SPH P2:OTE SVNY306-Field&Solie April15,2007 8:40 Introduction to Agricultural Engineering Technology i P1:OTE/SPH P2:OTE SVNY306-Field&Solie April15,2007 8:40 Introduction to Agricultural Engineering Technology A Problem Solving Approach Third Edition Harry L. Field and John B. Solie OklahomaStateUniversity Stillwater,OK,USA iii P1:OTE/SPH P2:OTE SVNY306-Field&Solie April15,2007 8:40 HarryL.Field JohnB.Solie OklahomaStateUniversity,Stillwater,OK, OklahomaStateUniversity,Stillwater,OK, USA USA 111AgriculturalHall 111AgriculturalHall Stillwater74078 Stillwater74078 [email protected] [email protected] LibraryofCongressControlNumber:2006930107 ISBN-10:0-387-36913-9 e-ISBN-10:0-387-36915-5 ISBN-13:978-0-387-36913-6 e-ISBN-13:978-0-387-36915-0 Printedonacid-freepaper. (cid:2)C 2007SpringerScience+BusinessMedia,LLC Allrightsreserved.Thisworkmaynotbetranslatedorcopiedinwholeorinpartwithoutthewritten permissionofthepublisher(SpringerScience+BusinessMedia,LLC233SpringStreet,NewYork, NY10013,USA),exceptforbriefexcerptsinconnectionwithreviewsorscholarlyanalysis.Use in connection with any form of information storage and retrieval, electronic adaptation, computer software,orbysimilarordissimilarmethodologynowknownorhereafterdevelopedisforbidden. Theuseinthispublicationoftradenames,trademarks,servicemarks,andsimilarterms,evenifthey arenotidentifiedassuch,isnottobetakenasanexpressionofopinionastowhetherornottheyare subjecttoproprietaryrights. 9 8 7 6 5 4 3 2 1 springer.com iv P1:OTE/SPH P2:OTE SVNY306-Field&Solie April15,2007 8:40 Contents 1. ProblemSolving................................................................ 1 2. SignificantFiguresandStandardForm.................................. 17 3. CommonUnitsofMeasure.................................................. 23 4. SimpleMachines............................................................... 36 5. InternalCombustionEngines............................................... 49 6. PowerTrains.................................................................... 61 7. TractorsandPowerUnits.................................................... 80 8. MachineryCalibration....................................................... 93 9. EquipmentEfficiencyandCapacity....................................... 118 10. EconomicsofAgriculturalMachinery.................................... 129 11. SoundandNoise................................................................ 152 12. MeasuringDistance............................................................ 159 13. AnglesandAreas............................................................... 175 14. LandDescription............................................................... 196 15. DifferentialandProfileLeveling........................................... 204 16. Weather........................................................................... 221 v P1:OTE/SPH P2:OTE SVNY306-Field&Solie April15,2007 8:40 vi Contents 17. WaterRunoff.................................................................... 234 18. ErosionandErosionControl................................................ 244 19. Irrigation......................................................................... 253 20. Handling,MoistureManagement,andStorageof BiologicalProducts............................................................ 266 21. AnimalWasteManagement................................................. 279 22. InsulationandHeatFlow.................................................... 286 23. Heating,Ventilation,andAir-Conditioning............................. 293 24. SelectionofStructuralMembers........................................... 319 25. PrinciplesofElectricity....................................................... 326 26. SeriesandParallelCircuits.................................................. 331 27. SizingConductors.............................................................. 340 28. ElectricMotors................................................................. 347 Appendices 356 Index 371 P1:GFZ SVNY306-Field&Solie March28,2007 8:35 1 Problem Solving 1.1. Objectives 1. Beabletodefineproblemsolving. 2. Beabletodescribethecommonproblem-solvingmethods. 3. Beabletoselecttheappropriatemethodforsolvingaproblem. 4. Understandthefunctionanduseofspreadsheets. 5. Understandtheuseofandcommonsymbolsforflowcharts. 1.2. Introduction Problem solving is a part of living. We are faced with a host of problems on a dailybasis.Someoftheseproblemsinvolvepeopleandhumanrelations,whereas othersrequireamathematicalsolution.Inthischapterwewilldealwithproblems involvingmathematicalsolutions,andseveralwaysinwhichtheseproblemscan beapproached. 1.3. Mathematical Problem Solving Mathematicalproblemsolvingistheprocessbywhichanindividualusesprevi- ouslyacquiredknowledge,skills,andunderstandingtosatisfythedemandsofan unfamiliarsituation.Theessenceoftheprocessistheabilitytouseinformation andfactstoarriveatasolution.Therearetwocharacteristicsofproblemsolving thatmustberememberedwhensolvingproblemsusingmathematicalprocesses. 1. The mathematical process does not always give you the answer—just more informationsothatyoucanmakeamoreinformeddecision.Gooddecision-making requiresgoodinformation. 2. Wheneverperfectionisnotpossibleorexpected,levelsorintervalsofaccept- abilitymustbeestablished.Whenperfectionisnotpossiblesomeonemustdeter- minetheamountoferrorthatisacceptable.Theacceptableleveloferrormaybe 1 P1:GFZ SVNY306-Field&Solie March28,2007 8:35 2 1. ProblemSolving determinedbystandards,manufacturers’recommendations,comparisontoanother situationsormachinesorpersonalexperience. Bothofthesecharacteristicswillbeutilizedandexplainedinmoredetailinlater chaptersbyusingexamples. Problemscanbesolvedindifferentways.Oneoftheobjectivesofthischapter istoincreasethereader’sknowledgeofproblem-solvingmethods.Sevendifferent approaches to solving mathematical problems will be discussed: diagrams and sketches,patterns,equationsandformulas,unitscancellation,intuitivereasoning, spreadsheets,andflowcharts. 1.3.1. Diagrams and Sketches Someproblemsinvolvethedeterminationofaquantityofitems,suchasthenumber of nails per sheet of plywood or the number of studs in a wall. In solving these typesofproblemsitusuallyishelpfultodrawasketchoradiagram. Problem: Howmanypostsareneededtobuildafence100ftlongwithposts10ft apart? Solution: Formanypeoplethefirstresponsewouldbe10: 100ft Posts= =10posts 10.0ft/post butadiagram,Figure1.1showsthatthecorrectnumberofpostsis11. This is an example of a situation where a wrong answer is possible if you do notinterprettheproblemcorrectly.Inthisexample,10isthenumberofspaces, notthenumberofposts. FIGURE1.1. Numberofposts. 1.3.2. Patterns Thesolutiontosomeproblemsmaydependuponone’sbeingabletodiscovera patterninanarrayofnumbersorvalues.Frequently,itisconvenienttoexaminethe patternsinasampleratherthantheentirepopulation.Onceapatternisdiscovered andshowntobeconsistentforthesample,itcanbeusedtopredictthesolution fortheentirepopulation. P1:GFZ SVNY306-Field&Solie March28,2007 8:35 MathematicalProblemSolving 3 TABLE1.1. Patternsinnumbers,firstsample. Cownumber Ration Child 1 2 3 4 5 6 7 8 9 10 Grain 1 N N N N N N N N N N Mineral 2 Y Y Y Y Y Hay 3 Y Y Y Silage 4 Y Y Water 5 Y Y Problem: Adairyfarmerhasfivechildren.Eachchildisresponsibleforonepart ofthedailyfeedrationforthefamily’s100dairycows.Theoldestisresponsible forthegrain,thesecondfortheminerals,thethirdforthehay,thefourthforthe silage,andthefifthforwater.Insteadoffeedingeachcow,thefirstchilddecides shewillnotfeedthecowsatallthatday.Thesecondchilddecidesjusttofeedevery other cow, the third child feeds every third cow, and so on. Dad soon discovers howthecowswerefed,andneedstoknowwhichcowsdidnotreceiveanyfeed orwater. Solution: Whenoneisfacedwiththistypeofproblem,itisusuallyhelpfultoset upatable.Inthiscase,itwouldbeverytime-consumingtosetupatableforall100 cows.Instead,selectasampleofthecows.Ifapatternistrueforthesample,there is a high probability that the pattern will be true for a large group. Determining thesizeofasampleisnotalwayseasy.Pickone,andifaclearpatterndoesnot appear, increase the size until a pattern develops. We will start with the first 10 cows,Table1.1. Inthissample,cows#1and#7didnotreceiveanygrain,mineral,hay,silage, orwater.Isthisenoughinformationtoestablishapattern?Wewillpredictthatthe nextcowthatdidnotreceiveanyfeedorwateris#11.Why?Totestthisprediction, thesamplesizemustbeextendedtoincludealargernumberofcows. Table 1.2 shows that the prediction was right; cow #11, along with #13, #17, and#19,didnotreceiveanygrain,minerals,hay,silage,orwater.Itisnowsafeto considerthatthepredictioncouldbeusedtoidentifyalloftheanimalswithinthe herdthatdidnotreceiveanygrain,minerals,hay,silage,orwater(thoseanimals representedbyprimenumbers,thatis,anumberdivisibleonlybyitselfandone). TABLE1.2. Patternsinnumbers,secondsample. Cownumber Ration Child 11 12 13 14 15 16 17 18 19 20 Grain 1 N N N N N N N N N N Mineral 2 Y Y Y Y Y Hay 3 Y Y Y Silage 4 Y Y Y Water 5 Y Y P1:GFZ SVNY306-Field&Solie March28,2007 8:35 4 1. ProblemSolving 1.3.3. Equations and Formulas Equationsandformulasareverysimilarproblem-solvingtools.Sometextsstudy themseparately,butinthissectiontheywillbecombined.Equationsareawayof showingtherelationshipbetweendifferentvariablesinaproblemandareusually derivedasneededforeachproblem.Formulasareequationsthatareusedfrequently enoughoraresomehowuniqueenoughthattheyarerememberedandusedwithout aderivation. 1.3.3.1. Equations Thesolutiontosomeproblemsrequiresthederivationofamathematicalequation based on a pattern or another type of relationship between the numbers. These equationswillbeuniqueforeachproblem. Problem: Howmuchwireisneededtobuildasinglewirefencearoundarectan- gularfieldmeasuring450ftlongand350ftwide? Solution: Inthisexampletherearethreequantities:length,width,andperimeter. It should be obvious that the perimeter is a function of the other two. Begin by assigning the variables L to represent the length, W to represent the width, and Prtorepresenttheperimeter.Then,becausearectanglehastwolengthsandtwo widths,theperimetercanbefoundasfollows: Pr=(L+L)+(W +W) Pr=(450ft+450ft)+(350ft+350ft) =900ft+700ft =1,600ft 1.3.3.2. Formulas Forsomeproblemstherelationshipsofthevariablesarefixedandconstant,sothe equationforthatproblemisrememberedandused.Theseequationsaresometimes calledformulas.Anothercharacteristicofformulasisthattheyusuallycontaina constant.Oneexampleistheareaofacircle:A=πr2.Thevariableπisaconstant. Thereareatleasttwoimportantconsiderationsinusingformulas. 1. Youmustenterthenumberswiththecorrectunitsofmeasure.Allformulasare designedwithspecificunitsforthenumbers,especiallyiftheyhaveaconstant.If the units are incorrect, the answer will be incorrect. An example is the equation usedtodeterminetheapplicationrateofaboomtypesprayer: gal 5,940×Flowrate(gal/min) Applicationrate = ac Speed(mi/hr)×nozzlespacing(in) It should be obvious that the units in the equation do not work (the units when combineddonotresultintheunitsforapplicationrate,gal/min).Thisequationis anexampleofasituationinwhichunitsconversionvalues,thatarealwaysused

Description:
Introduction to Agricultural Engineering Technology: A problem Solving Approach is an invaluable text for agriculture students at the introductory level. The third edition has been thoroughly updated and reorganized to meet the current units and standards of the American Society of Agricultural and
See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.