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VECTORANDTENSORCALCULUSFORENGINEERS
Slidingvectorsdetermineaphysicalquantitycorrectlyifthey
lieinthesamestraightline.Anexampleistheforcevector.The
efectofaforcevectorwillnotchangeaslongasitisapplied
toanypointalongthedirectionofthevector.Boundvectors
haveaspecificpointofapplication.Thisisexemplifiedbythe
displacementvectorofaspecificpointofadeformablebody,the
velocityorthedisplacementvectorsofaspecificpointofarigid
bodyinitsfreemotion.
Thisclassificationofvectorsinmechanicsisimportantand
assignmentofthegivenvectortotheincorrectgroup,while
retainingthethreebasicvectorproperties(magnitude,direction
andsense),couldleadtoawrongphysicalinterpretationofthe
mathematicaloperationsonvectors.Vectorsareequivalentif
theyrepresentthesamevectorquantity.Twofreevectorsare
alwaysequivalent.Slidingvectorsareequivalentiftheyliein
thesamestraightline.Boundvectorsareequivalentiftheyare
appliedtothesamepoint.
1.2.Designationofvectors
1.2.1.Vectoraddition
Avector(morespecifically:aboundvector)beginningatAand
endingatBisanorganisedpairofpointsAandB.Avector

ą
beginningatAandendingatBisdesignatedas
AB
.Vectorswill
bealsodesignatedwithboldletters,e.g.a,b,c.Thedistance
betweenpointsAandBisthelengthoformagnitudeofvector

ą

ą
AB
anddesignatedas
AB
orABor,accordingly,thelengthof

ą
vectoraby
a
ora.Thesenseofthe
AB
vectoristhesenseof
theABray.Twovectorshavethesamedirectionifthestraight
linesdeterminedbythesevectorshavethesamedirection.Two
vectors,aandb,arecalledequaliftheyhavethesamedirection,
thesamesenseandthesamelengths.Twovectorsarecalled
oppositeiftheyhaveequallengths,thesamedirection,but
oppositesenses.Thevectoroppositetoaisdesignatedas
a
.
Azerovector0isavector,theinitialandterminalpointsof
whichcoincide.
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