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题目:小船由A港到B港顺流需行6小时,由B港到A港逆流需行8小时.一天,小船从早晨6点由A港出发顺流行到B港时,发现一救生圈在途中掉落在水中,立刻返回,一小时后找到救生圈.问: (1)若小船按水流速度由A港漂流到B港需要多少小时? (2)救生圈是在何时掉入水中的? (1998,天津市中考题) 这是一道“水流”应用题,第1问比较简单,列方程或方程组求解.第2问较难,因此,笔者特对该题从几个不同视角进行分析并给出相应的解法.
Subject: Boats from A to B will take 6 hours to catch, and B to A will take 8 hours to backflow. One day, the boat departs from A port at 6 am After falling in the water on the way, return immediately and find the lifebuoy one hour later. Q: (1) How many hours will it take for the boat to drift from A to B at the flow rate? (2) When did the lifebuoy fall into the water? 1998, Tianjin Examination Questions) This is a “water flow” application problem. The first question is relatively simple. It lists equations or equation sets. The second question is more difficult. Therefore, the author specifically analyzes this question from several different perspectives. Give the corresponding solution.