PHY 102 1st Edition Lecture 6 Outline of Last Lectture I Blue Boo ok Problems Outline of Current Lecture I II III Motion Uniform mly Accelerated Motion n UAM Blue Boo ok 3 1 Currentt Lecture I Motion Rectilinearr a TThe simplesst kind of mo otion takes place on a sstraight linee b TThree quanttities that describe thiss motion i Distaance displaacement ii Speeed velocityy 1 1 meters second m s iii Acce eleration Quaantities in bold can be p positive or n negative c TThe simplesst kind of rectilinear mo otion is unifform motion n in which vvelocity d does not change i x vvt ii speeed distancce time 1 1 v x t iii 1 miile per hour 1 mile 1 hr 1610 m m 3600 s 0 4472 0 m s 1 1 Examplee IL speed liimit 70 mph 70 0 4472 31 3 3 m s iv The best way to o learn rectilinear motio on is graphss 1 1 Plot velo ocity versus time on a ggraph 2 2 Distancee velocity aand acceleraation can bee easily iden ntified on such a graph 3 3 Uniform m motion veelocity as a function f of time These notes represent a d detailed interp pretation of th he professor s lecture Grad deBuddy is besst used as a supplement to your own notes n not as a substitute II How do you u represent tthe distancee on such a graph a H H do you How u find the disstance coveered in 15s 8 15 geo ometry height h width A AREA 4 4 Area ass distance is not limiteed to uniforrm motion It can be used in general g a Of O course yo ou can t multiply velociity by time b because v velocity keeps changingg in a general motion b But B if your time intervaal is very sho ort velocity is almost c constant during that tim me and you u can use the d distance as area idea i Break up the large time in nterval into a lot of very short small intervals ulate the disstance for eeach short in nterval ii Calcu and aadd them all together 5 5 So far we w have learrned how to o find the veelocity and distance d for a mo oving objectt a For F velocity read off th he plot valuee For distance m measure thee area undeer the v t curve 6 6 What ab bout accelerration a acceleration a n change in velocity ttime a v t U meters second2 m ss Unit b Instantaneo ous acceleration a v t t is verry small c Remember R v can be either positivve or negatiive i a 0 means velo ocity increases speeding up ii a 0 means velo ocity decreaases slowin ng down d Graphically G tangent line is the time Uniform mly Accelerated Motion n UAM III a A Acceleration n does not cchange b SSlope does not change straight lin ne mx b i y m c v at vo d d distance aarea of trapeezoid areaa of rectanggle area off triangle i areaa of rectangle tvo vot ii areaa of triangle t v vo at2 e x vot att2 i a can n be either positive or negative Blue Boo ok 3 1