Problem $13\mathrm{.}169$ The river flows north at $3$ m$/$s$.($Assume that the current is uniform.$)$ If you want to travel in a straight line from point C to point Din a boat that moves at a constant speed of $10$ m$/$s relative to the water, in what direction should you point the boat? How long does it take to make the crossing? underline v theta$*$fw $=10$cos theta $*$ i $+$ io $*$ sin theta $*$ j mis y$\_\{$m$\}=3*$ j $*$ m $/$ s VB $=$ VB$/$W $+$ Y $=$ i$*$theta $*$ cos theta $*$ j $+$ i$*$theta $*$ sin theta $*$ j $+3*$ j m$/$s $10$ COSO $+$ Closing$+3)500$ B$/$W $3$ Since YBICO $(10$sin theta $+3)/(10$cos theta$)=$ tan alpha $=4/5$ alpha $=38\mathrm{.}66$ s $*0$sin theta $+$is$^-=40$ cos theta $4$cos theta $-5$sin theta $=1\mathrm{.}5$ nu $*$ cos theta $-(5/($sqrt$(41)))*$ sin theta $=($i $*5)/($sqrt$(41))$ Sind Cost$-$cosasinD $=0-2343$ n$((-$ theta$)=0\mathrm{.}2343<$ theta$=$sin$^-$ prime $(0-23431=13$s $*5^0$ theta $=$ alpha $-12*55$ deg $=2$s $*$ t deg B $=1000325\mathrm{.}11+(105$n $25\mathrm{.}11+3)$ j tcp $(3)=1004111\mathrm{.}64$ VB$)=11\mathrm{.}6$ m$/$s$.=55$:$25.$ Val $=55002+400=10059118\mathrm{.}1700$ whey boinimum speed must a boat have relative $10$ m$/$s