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求解物理学中的习题或实际问题,一般所解得的结果是唯一确定的(某些象黑盒子之类物理题,它不在我们讨论的范围之内)。然而解题中有时也会发生一道习题几种结果的情况,往往会出现以下几种情况。一、解的表达形式不一样,实质相同。例题1:一火车沿直线轨道从静止出发由A地驶向B地,并停止在B地。A、B两地相距s。火车做匀加速运动时,其加速度最大为a_1;做匀减速运动时,其加速度的绝对值最大为a_2,由此可以判断出该火车由A到B所需的最短时间为____。(第三届全国中学生物理竞赛试题) 本题发生的物理过程是:火车由A地从
When solving problems or practical problems in physics, the results usually obtained are uniquely determined (some physical problems such as black boxes, which are not within the scope of our discussion). However, sometimes there are several results of a problem in the problem solving, and the following situations often occur. First, the expression of the solution is not the same, the essence is the same. Example 1: A train travels from a standstill in a straight line from A to B and stops at B. A, B are s apart from each other. When the train performs uniform acceleration motion, the maximum acceleration is a_1. When the uniform deceleration movement is performed, the absolute value of the acceleration is a_2 at the maximum, and thus the shortest time required for the train from A to B can be judged as ____. (The 3rd National Middle School Student Physics Contest Question) The physical process of this question is: Train from A