[填空题]
A boat, whose speed in still water is 1.75 m/s, must aim upstream at an angkdz/:v xi8i)d:kzi,qotz:*6 :rt e a xlcthsa yd+p;s5(-yjo*zdku 328hq xw)ycf0)w e of -o px+0jyt z*w)8y2ud 3(h;qhd fc ck) s5swya$26.3^{\circ}$ (with respect to a line perpendicular to the shore) in order to travel directly across the stream. (a) Determine the speed of the current. $m/s$ (b) Determine the resultant speed of the boat with respect to the shore $m/s$
