{VERSION 5 0 "APPLE_PPC_MAC" "5.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 1 }{CSTYLE "2D Output" 2 20 "" 0 1 0 0 255 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 257 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 259 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 260 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 261 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 262 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 263 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 264 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Warning" -1 7 1 {CSTYLE "" -1 -1 "Courier" 1 10 0 0 255 1 2 2 2 2 2 1 1 1 3 1 } 1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Maple Output" -1 11 1 {CSTYLE " " -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 3 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Maple Output" -1 12 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }1 3 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Map le Plot" -1 13 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Heading 1" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 18 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }3 1 0 0 8 4 1 0 1 0 2 2 0 1 }{PSTYLE "Normal" -1 257 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {EXCHG {PARA 256 "" 0 "" {TEXT -1 31 "Test 1 solutions (pink v ersion)" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 49 "1 (10 points). Calculate the following:\n\n\n\na) \n" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 57 "vec := t -> crossprod([0, 3*t ,6*t \+ ], [exp(t), t ,2*t ]);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%$vecGf*6#% \"tG6\"6$%)operatorG%&arrowGF(-%*crossprodG6$7%\"\"!,$9$\"\"$,$F2\"\"' 7%-%$expG6#F2F2,$F2\"\"#F(F(F(" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "map(diff,vec(t), t);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'vec torG6#7%\"\"!,&-%$expG6#%\"tG\"\"'*(F-\"\"\"F,F/F)F/F/,&F)!\"$*(\"\"$F /F,F/F)F/!\"\"" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 4 "b) " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "map(int,[cos(t/2),t/(t^2-1)], t=2.. 5);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#7$,&-%$sinG6##\"\"&\"\"#F**&F* \"\"\"-F&6#F,F,!\"\",$-%#lnG6#F*#\"\"$F*" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 84 "This is the best frm of the answer, but in case you prefe r numerical approximations:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "evalf(%);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#7$$!*#o(*f[!\"*$\"+r2s R5F&" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 252 "2 (10 points). On the c urve shown below, clearly indicate\n\na) the unit tangent vector at \+ the point P. Label it T\n\nb) the principal unit normal vector at the point P. Label it N\n\nc) at least one point where the curvature is \+ maximized. Label it M.\n" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 " " 0 "" {TEXT -1 97 "For part a), the unit tangent vector can point in \+ either direction. For part b), the unit normal" }}{PARA 0 "" 0 "" {TEXT -1 99 "vector should point to the inside of the curve and have t he same length as T. For part c, M should" }}{PARA 0 "" 0 "" {TEXT -1 31 "be where the curve is sharpest." }}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 0 "" 0 "" {TEXT -1 112 "In problems 3 and 4, an object of ma ss 2 moves along the helix\n\n\011r(t) = 2 cos(3 t^2) i + t^2 j + 2 si n(3 t^2) k\n" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 52 "r := t -> v ector([2*cos(3*t^2),3*t^2,2*sin(3*t^2)]);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%\"rGf*6#%\"tG6\"6$%)operatorG%&arrowGF(-%'vectorG6#7% ,$-%$cosG6#,$*$)9$\"\"#\"\"\"\"\"$F8F4,$-%$sinGF3F8F(F(F(" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 24 "First, let's look at it:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 80 "with(plots): spacecurve([2*cos(3*t^ 2),3*t^2,2*sin(3*t^2)], t=0..2, axes=NORMAL);" }}{PARA 7 "" 1 "" {TEXT -1 50 "Warning, the name changecoords has been redefined\n" }} {PARA 13 "" 1 "" {GLPLOT3D 349 262 262 {PLOTDATA 3 "6$-%'CURVESG6#7T7% $\"\"#\"\"!$F*F*F+7%$\"+@](***>!\"*$\"+Mv\"z*\\!#7$\"+aMz&***F27%$\"+Y .g**>F/$\"+9q;**>!#6$\"+*pn!)*RF:7%$\"+Gq(z*>F/$\"+#yD\")\\%F:$\"+k\"= K**)F:7%$\"+P(3O*>F/$\"+`!om*zF:$\"+?'Hwf\"!#57%$\"+8$3W)>F/$\"+$Qz%\\ 7FK$\"+a:Y#\\#FK7%$\"+BUrn>F/$\"+6.D*z\"FK$\"+0j6zNFK7%$\"+TTKS>F/$\"+ !fz*[CFK$\"+&fY\"\\[FK7%$\"+pYb)*=F/$\"+>sm)>$FK$\"+64!))G'FK7%$\"+%pP $Q=F/$\"+*>8$[SFK$\"+5WFxyFK7%$\"+kZOb(FK$\"+)Q=$=8F /7%$\"+h*))zK\"F/$\"+C1[Y%)FK$\"+[\\Z&\\\"F/7%$\"+gHs96F/$\"+c$=fz*FK$ \"+*))R0m\"F/7%$\"+\\Y)>j)FK$\"+W9`C6F/$\"+H48/=F/7%$\"+')z^WdFK$\"+() oYz7F/$\"+Xds:>F/7%$\"+lsB@DFK$\"+m\")RW9F/$\"+kZ/%)>F/7%$!++8)>q*F:$ \"+z_K>;F/$\"+.ak(*>F/7%$!+qJuEYFK$\"+G#[U!=F/$\"+!GZd%>F/7%$!+a^y2$)F K$\"+6q;**>F/$\"+9vG>=F/7%$!+yBf$=\"F/$\"+I;3/AF/$\"+k_<7;F/7%$!+Eo<+: F/$\"+%3#**=CF/$\"+F^nA8F/7%$!+(Hrtv\"F/$\"+s$)*Qk#F/$\"+]h,[&*FK7%$!+ 0oLJ>F/$\"+'\\+)yGF/$\"+'=db>&FK7%$!+1)z'**>F/$\"+d%)pBJF/$\"+f#['yNF: 7%$!+4O4W>F/$\"+bAfyLF/$!+'=Vdp%FK7%$!+*\\]Lv\"F/$\"+()=[VOF/$!+2Gl@'* FK7%$!+XiNE9F/$\"+btO=RF/$!+8d'>S\"F/7%$!+cd`[(*FK$\"+e'[K?%F/$!+?xKY< F/7%$!+w.b_UFK$\"+'zD\")\\%F/$!+amEa>F/7%$\"+zqr4=FK$\"+q()*H![F/$!+#[ &z\"*>F/7%$\"+D><*)yFK$\"+zv'y6&F/$!+Iu#y$=F/7%$\"+V2DM8F/$\"+BAtUaF/$ !+@4*)*[\"F/7%$\"+H_x\\lo*FK7%$\"+B%>U(>F/$\"+=!\\ C7'F/$!+r4!4?$FK7%$\"+0sVi>F/$\"+o6IxkF/$\"+G:)z&QFK7%$\"+%45cp\"F/$\" +`\"\\@%oF/$\"+_ghg5F/7%$\"+4Zb*=\"F/$\"+uH*p@(F/$\"+a4y2;F/7%$\"+g;r* )\\FK$\"+IE$=g(F/$\"+DqvO>F/7%$!+8i0WGFK$\"+@\"om*zF/$\"+&3v'z>F/7%$!+ $**Q6/\"F/$\"+[%*\\,%)F/$\"+.'Qwq\"F/7%$!+6%o5k\"F/$\"+5mK;))F/$\"+`[> V6F/7%$!+r_Pm>F/$\"+2'\\6C*F/$\"+)Ri>l$FK7%$!+7WBP>F/$\"+S%ofn*F/$!+r] 9r\\FK7%$!+l#>[`\"F/$\"+6$y?,\"!\")$!+XUJ#G\"F/7%$!+%=c[:)FK$\"+h$fv0 \"Fc_l$!+RO>E=F/7%$\"+)HI@'*)F:$\"+&**RS5\"Fc_l$!+'*4*z*>F/7%$\"+PE9J* *FK$\"+7-_^6Fc_l$!+#33gt\"F/7%$\"+f!3xo\"F/$\"+8+++7Fc_l$!+8c9t5F/-%*A XESSTYLEG6#%'NORMALG" 1 2 0 1 10 0 2 1 1 4 2 1.000000 45.000000 45.000000 0 0 "Curve 1" }}}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 57 "3 (10 \+ points). \n\na) The speed of the object at t= 3 is" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "with(linalg): map(diff,r(t),t): nor m(%, 2);" }}{PARA 7 "" 1 "" {TEXT -1 80 "Warning, the protected names \+ norm and trace have been redefined and unprotected\n" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*$-%%sqrtG6#,(*$)-%$absG6#*&-%$sinG6#,$*$)%\"tG\" \"#\"\"\"\"\"$F7F5F7F6F7\"\"%*$)-F,6#F5F6F7F7*&F9F7)-F,6#*&-%$cosGF1F7 F5F7F6F7F7F7\"\"'" }}}{EXCHG {PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 19 "which simplifies to" }{TEXT 256 1 " " } {TEXT -1 28 "6 t sqrt(5). At t=3, it is " }{TEXT 257 9 "18sqrt(5)" } {TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 118 "b) Tthe length of the curve between the points (2,0,0) \+ and (-2,3 \271,0) is the same as the curve from t=0 to t=sqrt(\271):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "int(6*t*sqrt(5), t=0..sqr t(Pi));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*&-%%sqrtG6#\"\"&\"\"\"%# PiGF)\"\"$" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 62 "c) As for the tang ent line at t=sqrt(\271)/3, it passes through " }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 14 "r(sqrt(Pi)/3);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'vectorG6#7%\"\"\",$%#PiG#F'\"\"$*$-%%sqrtG6#F+F'" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 39 "and has direction given by the velocity" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 17 "map(diff,r(t),t);" }} {PARA 11 "" 1 "" {XPPMATH 20 "6#-%'vectorG6#7%,$*&-%$sinG6#,$*$)%\"tG \"\"#\"\"\"\"\"$F1F/F1!#7,$F/\"\"',$*&-%$cosGF+F1F/F1\"#7" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 16 "at t= sqrt(\271)/3:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 22 "subs(t=sqrt(Pi)/3, %);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'vectorG6#7%,$*&-%$sinG6#,$%#PiG#\"\"\"\"\"$F/-%%sqrt G6#F-F/!\"%,$*$F1F/\"\"#,$*&-%$cosGF+F/F1F/\"\"%" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simplify(%);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'vectorG6#7%,$*&-%%sqrtG6#\"\"$\"\"\"-F*6#%#PiGF-!\"#,$*$F.F-\"\" #F2" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 17 "Hence the line is" }}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 257 "" 0 "" {TEXT -1 83 "R(u) = (1 - 2 sqrt(3 \271) u) i + ( \271/3 + 2 sqrt(\271) u) j + (sqrt(3) + 2 sqrt(pi) u) k. " }}{PARA 0 " " 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 258 1 "4" }{TEXT -1 2 ". " }}{PARA 0 "" 0 "" {TEXT -1 65 "a) Find the force on \+ the object in the moving coordinate system." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "There is no " }{TEXT 259 1 "B" }{TEXT -1 63 " component, because the force is just 2* acceleration, w hich is" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 10 " s'' " }{TEXT 260 1 "T" }{TEXT -1 12 " + (s')^2 k " }{TEXT 261 1 "N" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 " " 0 "" {TEXT -1 72 "hence we need to calculate the speed, its derivati ve, and the curvature." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 27 "We already know the speed, " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "speed := t -> 6*sqrt(5)*t;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%&speedGf*6#%\"tG6\"6$%)operatorG%&arrowGF(,$*&-%%sqrt G6#\"\"&\"\"\"9$F2\"\"'F(F(F(" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 128 "so the acceleration is 6 sqrt(5). The only tricky part is the curv ature, but since the curve is a helix, it won't be too bad." }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 48 "crossprod(map(diff,r(t),t), \+ map(diff,r(t),t$2));" }}{PARA 12 "" 1 "" {XPPMATH 20 "6#-%'vectorG6#7% ,&*&%\"tG\"\"\",&*&-%$sinG6#,$*$)F)\"\"#F*\"\"$F*F2F*!#s*&\"#7F*-%$cos GF/F*F*F*\"\"'*(\"#sF*F8F*F)F*!\"\",&*(F8F*F)F*,&*&F8F*F2F*F5*&F7F*F-F *F=F*F7**F7F*F-F*F)F*F+F*F*,&*&F-F*F)F*F5*(F:F*F)F*F@F*F=" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 39 "simplify(norm(%,2)/(6 * sqrt(5)* t) ^3);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*(,(-%$absG6#*&,&!\"\"\"\"\" *$)-%$cosG6#,$*$)%\"tG\"\"#F,\"\"$F6F,F,F,)F5\"\"'F,F,*&\"\"%F,)-F'6#F 5F9F,F,-F'6#*&F.F,F8F,F,#F,F6F5!\"$\"\"&FB#F6\"#D" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 146 "Come on, Maple, can't you see the common factor o f t^3 in the numerator and denominator? And what about the cancellati on of the cosines? Sheesh!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 17 "curvature := 2/5;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%*curvatureG #\"\"#\"\"&" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 4 "The " }{TEXT 262 1 "T" }{TEXT -1 19 " component is " }{TEXT 264 10 "12 sqrt(5)" } {TEXT -1 12 " and the " }{TEXT 263 1 "N" }{TEXT -1 13 " component i s" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "2* speed(t)^2 * curvat ure;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*$)%\"tG\"\"#\"\"\"\"$W\"" } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "33 0 0" 0 } {VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 } ÿ