(1) According to the meaning of the question, the distance between Party A and Party B is 24km, and it takes 4 hours for Party B to sail against the current, so the speed of water flow is 6km/h, while the time for Party A to swim against the current is 0.5 hours from 2 hours to 2.5h hours, so it takes 0.5*6=3km.

(2) According to the meaning of the question, if the still water speed of the ship is Xkm/h and the current speed is Ykm/h, then equation 4(x-y)=24, and equation 2(x+y)-(2.5-2)(x-y)+(x+y)=24, where 2 (x+). The last one (x+y) represents the distance traveled by the ship from 2.5h to 3.5h. The above two equations are combined into equations and solved to get x = 7.5 and y = 1.5, so the four-point coordinates of the image of Y 1 are (0,0), (2, 18. Further, according to the functional relationship between the proportional function y=kx and the linear function y=kx+b, Y 1 = 9x (0h ~ 2h), y 1 =-6x+30 (2h ~ 2.5h), and y1=

(3) If the lifebuoy falls into the water m hours after the departure of Ship A (m is less than 2), the equation 1.5(2-m+0.5)+0.5 * 6 = (7.5+1.5) (2-m) is obtained according to the meaning of the question, where/kloc-0. (7.5+ 1.5)(2-m) means that Ship A travels downstream for 2-m hours, that is, the distance from the lifebuoy falling into the water. To solve this equation, x= 1.5, so 1.5*(7.5+ 1.5) is 65433.

Since there are no specific graphics, we can only build our own graphics to solve the problem according to the general idea of the topic. Is that correct? Please forgive the shortcomings!