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第十四届全国初中物理竞赛(四川初二组)初赛有这样三道题。题目1:甲、乙两同学在跑道周长为400m的标准田径场上练习赛跑,已知甲、乙的速度分别为8m/s和7.5m/s,且各自保持快慢不变,某一时刻两人同时在相同起点处向同一方向起跑,经过多长时间后他们将再次相遇?这时甲已跑了几圈?分析:甲乙二人在园形跑道上从同一地点同时沿相同方向绕行是行程问题中的同向相遇,由于跑道是园形的,两人可长期跑下去,两人在运
The fourteenth national junior high school physics competition (Sichuan junior two group) preliminary game has these three questions. Topic 1: Classmates A and B practice running on a standard track and field track with a perimeter of 400m. Known speeds of A and B are 8m/s and 7.5m/s, respectively. They both start at the same starting point in the same direction. After how long will they meet again? Has A ran a few laps? Analysis: Both A and B circulated in the same direction from the same spot on the park runway. It is the same direction in the itinerary problem. Because the runway is in a garden shape, the two can run for a long time and the two are in operation.