Conceptual Questions. Fig Fig.1.27 EXERCISES

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1 XRISS oncepual Quesions. The number of decimal places in a measuremen along wih he uni is an indicaor of he precision of an insrumen. escribe wha kind of insrumens can be used o produce measuremens of m,. m,. m,. m, and. m.. Having measured an objec and found i o be. m, you hen spli i ino hree equal pieces and quoe he value m as he lengh of one of hese pieces. This is wha your calculaor produces when you divide. by 3. Is his value reasonable? Wha is i implying? 9. o all he people on he roor ride (Fig..6) have he same velociies and speeds a any given ime? xplain. Fig..6 see suden ex. 3. Using dollars and cens as he unis for any numbers you wish o use, explain why keeping your unis consisen is imporan when adding and subracing quaniies. 4. Name hree oher scalar and vecor quaniies besides he ones menioned in his chaper. 5. esign an odomeer and a speedomeer ha can be used o measure vecor quaniies. Remember, we now have access o saellie mapping sysems. 6. Sae hree examples where he displacemen is equal in magniude o he disance ravelled bu no equal o he acual disance ravelled. 7. Using examples, explain why wo vecors of equal magniude are no necessarily equal. 8. You have bough a Ferrari. On your rip, you had an average speed of 8 km/h, ye an average velociy of km/h (magniude only). How is his possible?. Skech a d! - represenaion of a ypical m dash. Remember ha spriners do no increase heir speed for he full m. In many cases, hey slow down near he end.. Skech a d! - graph for he 4 m run. Why is i differen from he m skech? How can hese graphs be used o help improve performance for an ahlee?. Look a he d! - graph in Fig..7. xplain which pars of he graph you would use o find he average speed, he average velociy, and he insananeous velociy. Fig..7 Posiion Time 3 uni a: Moion and Forces

2 3. a) onsider he wes direcion o be posiive. person is moving a 5 km/h, a a place 3 km from he saring poin. escribe where she is and which way she is ravelling. b) Using he sandard reference frame, describe he Superman ride menioned in he chaper in erms of displacemen and velociy. 4. an an objec have a) a posiive velociy and a negaive displacemen? b) a negaive velociy and a displacemen of zero? c) a value for disance and an average speed of zero? xplain each case. Problems. Terms and Unis 5. onver he following imes. ll unis mus be shown as well as cancellaions. a) minues o seconds b) 6.5 hours o minues c).6 days o hours d) 4.5 years o seconds e) 453 seconds o hours f).35 minues o years 6. For a ime of 5 s, sae he value using each prefix. Use boh decimal and scienific noaion. a) micro b) milli c) kilo d) mega 7. onver he following speeds. Show all unis as well as cancellaions. a) 5 km/h o m/s b) 5 km/h o m/s c). m/s o km/h d) 5 m/s o km/h 8. a) n average person is 75 cm all. How many people could you sack one on op of anoher o reach he op of he N Tower (553 m)? b) If inch.54 cm and inches foo, how all is he N Tower in fee? 9. a) The maximum speed reached by a sanding skae boarder is abou 4.7 m/s. Would he skaeboarder ge a icke in a 3 km/h speed zone? b) snail crawls imes slower han a normal human walk (3 km/h). How many imes slower han he skae boarder is he snail?. For he roller coaser in Fig..8, esimae he displacemen and disance ravelled for he following secions: a) o b) o c) o d) o e) o Fig..8. Four people se ou o measure a field s perimeer. They find ha Side. m, Side m, Side.5 m, and Side m. Taking ino accoun significan digis, a) wha is he perimeer, in meres and in millimeres? b) wha is he sum of? see suden ex. chaper : Posiion-Time Graphs 3

3 c) of? d) of? e) Wha would accoun for he differen number of decimal places in he measuremens?. Wha is he difference in heighs for he following measuremens? a) 5.7 m and 3. m b) 5.7 m and m c) cm and m d) 3.9 km and 3.9 mm.3 The Meaning of Negaives in Kinemaics 5. person is walking 3 km/h in a rain ha is moving 7 km/h wes. In he sandard reference sysem, wha are he person s wo possible velociies as measured by a cop using a radar gun parked on he side of he road?.4 Three Seps o Graphical nalysis 6. opy he graphs in Fig..3 ino your noebook and draw a line of bes fi for each. Indicae any poins ha are anomalies. Fig For he pahs aken in Fig..9, sae he displacemen using he sandard reference sysem. Fig..9 d d d 3 d d d 3 d d d (e) d d 3 d d cm 5 m 4. For he moions in Fig..3, describe he velociy in erms of a reference sysem where norh is negaive and eas is posiive. Fig..3 W N S cm 5 m/s W N S 7. For he graphs in Fig..3, sae he unis for a) slopes aken from he graphs. b) areas aken from he graphs. Fig..3 (km) m (kg) (h) V (m 3 ) l (m) F (kg m/s ) w (m) d (m) 3 uni a: Moion and Forces

4 .5 nalysis of Sraigh-Line d! - Graphs Fig For he graph in Fig..33, describe wha he person is doing in each marked secion. see suden ex. Time (s) isplacemen (m) Fig H G F (s) 3. The X-5- ravels a abou six imes he speed of sound (Mach 6). Use he daa in Fig..36 o creae a d! - graph. Find he velociy and conver i o km/h. Fig For he graph in Fig..34, calculae a) he slope for each secion. b) he area for each secion (his is pracice for he nex chaper). Fig..34 see suden ex (s) 3. Find he velociy for each secion in Fig Using he daa in Fig..35 for a Formula car, a) plo a labelled d! - graph and find he velociy of he car. b) onver he velociy o km/h. Time (s) isplacemen (m) Use he ickerape daa in Fig..37 o creae a d! - able and a d! - graph, hen find he objec s velociy. The period of he icker (ime beween dos) is.4 s. chaper : Posiion-Time Graphs 33

5 Fig Graph he daa from Fig..37. ssume ha all measuremens of displacemen are negaive..6 nalysis of urved-line d! - Graphs 35. opy he graphs in Fig..38 ino your noebook and draw curves of bes fi. Then draw in hree represenaive angens for each curve. Fig opy he graphs in Fig..4 ino your noebook. raw a angen a he poin indicaed and find is slope. Fig (s) (s) (s) (s) escribe wha is happening in he following graph by idenifying moion secions. ssume posiive is up. Fig For he following daa of a car, draw a d! - graph and describe he moion. raw angens a, 4, and 6 s, and find heir slopes. onver he values o km/h. Time (s) isplacemen (m) opy he graph in Fig..39 ino your noebook and draw one angen per secion. 4. a) For he ickerape daa in Fig..4, measure he displacemens, creae a d! - char, hen plo he values on a d! - graph. Find he curve of bes fi, draw four angens, and find heir slopes. Is his objec speeding up or slowing down? (T.5 s) b) hange your displacemen values o negaive. Repea he graphing procedure and find he slopes of he angens. Is he objec speeding up or slowing down? 34 uni a: Moion and Forces

6 Fig..4 STRT N Fig a) For he ickerape daa in Fig..4, measure he displacemens, creae a d! - char, hen plo he values on a d! - graph. Find he curve of bes fi, draw four angens, and find heir slopes. Is his objec speeding up or slowing down? (T.5 s) b) hange your displacemen values o negaive. Repea he graphing procedure and find he slopes of he angens. Is he objec speeding up or slowing down? Fig verage and Insananeous Velociies 4. For he graph in Fig..43, find he average velociy beween he poins indicaed. Fig (s) For he graphs in Fig..44, find he average velociy, as well as he insananeous velociies a he beginning and end of he ime period indicaed. alculae he average of he insananeous values and compare hem o he average velociy obained graphically (s) (s) 44. person walks 5 m [up] a fligh of sairs in. min, hen wais 5 s while being hooked up o a bungee cord. He jumps off, falls 55 m in 5. s, hen sops and bounces back m in. s before evenually coming o res. raw a represenaive d! - graph. Remember o include a slowing-down secion as he free fall was 5 m in heigh. You can add exra secions for he person bouncing o a complee sop if you wish. chaper : Posiion-Time Graphs 35