arc considered optional. They can be o

42. An :"'cTage family of four uses roug hl y 1200 li(ers (ahou(.lOIlgallo",) of waler per day. (Oneliler 5 UXXlcm'.)How much delHh wo uld n lah k~ Pdjaccol molecules jusltouching. eSlimalc the di.meler of Ihe oil slick. AssumeIh~ oil mol~eulc, ha"c a diameter of2 X 10 10 m." .51.52.kan cam fJS besid~ a wide rivcr and "'noders h"w "'ide ili .. She SpolS a large rock on th e bank directly aero .. fromher. Shc Ihen wa lk s u pSlr~a m unlil 'he judges Ihat Ih~angle bclween her a nd the rod. which she CHn still secclearly. i, no'" at a n angle of J()" dO"'nstream (Fig. 1-17).JC;ln "'e,.. ureS her stride 10 be aboul one yard long. Thed islance back to her camp is 12Uslride~ ,\ bo Ul how faracross. bolh in yard, and in md~'" i, the river?, , , , ,.. , ,, N''"', , ," FIGURE 1- 17I'roblem 49.,\ "'aleh manUfatlllrer claim' that ils watches gain orIme no more Ihan ~ second, in a year. H"w accurale i,this walch. exprcs,cd as a percentage?The diameler of Ihe M""n is 3480 ~m . Whal is Ihe ,'"Iumeof Ihe Moon' How many Moons would he needed 10creale a "olume e'lual 10 Ihat of Earth?An angSlrom (s)"mbol A) is a unil of lenglh. defined asIO-''' m. ""hich is on the order of the diameler of an alom.In) How many nanomders are in 1.0 ang'trom? (b) Howma1\)' fem(metcrs or ferm is (Ihe COmmon unit of lenglhin nuclear physics) are in 1.0angslrom·! (e) Ho"" man~'nns'troms arc in 1.0 melcr? (,/) How m.nj· M gstroms arcin I.U light·year (sec Problem 22)?D el~rm ine Ih~ jk":ent unC ~rl ainll" in d. and in sin 1/ .... hen(n) 8 = 15.0' ± OS. (b) 1/ = 75.0" ± 0.5.If you !>egan walking along one of Earth's lines oflongitude and walked unlil you had changed lalitude by1 minute of arc (there arc 60 minut~s jkr degree). ho'" farwould you h,..-e walked lin miles)' This diSla nce is c;llieda "nau!ical mile:'Answers to ExercisesA: (d).8: No: 3. 2.C: Alllhree have Ihree 'ignifiear1( figures. alihough Ihenum""r of decimal places is (nl 2. (h) 3. (c) ~.U: M I. E \"Cr~st. 29.035 flo K2. 28.25 1 It: KangchenjungJ.2ll.169ft.E: No 15 mls '" :l4 milh18 CHAPTER 1 In troduction, Measurement, Estimating