小学高年级的同学在解答应用题时,有时会遇到一类列车过桥(或隧道)的题目。列车过桥,应从车头上桥起,算到车尾离桥为止。由于列车车身具有一定的长度,所以我们应当把车长和桥长的和看作列车过桥的路程。由“路程÷速度=时间”的数量关系,可把这类题目归为以下四类:一、求列车过桥(或隧道)的时间当题目告诉车长、桥(或隧道)长和车速这三个条件,求列车通过桥(或隧 Students in high school level sometimes encounter a type of train crossing the bridge (or tunnel) when answering application questions. Train crossing the bridge, should be from the front of the bridge, counting the car from the bridge so far. Since the train body has a certain length, we should consider the length of the conductor and the length of the bridge as the distance the train crosses the bridge. From the “distance ÷ speed = time” the relationship between the number of such topics can be grouped into the following four categories: First, find the train crossing the bridge (or tunnel) When the topic tells the conductor, bridge (or tunnel) and Speed ​​these three conditions, seeking train through the bridge (or tunnel