一客运列车甲匀速行驶，其车轮在铁轨间的接缝处会产生周期性的撞击。坐在客车甲中的某
旅客测得从第1次到第16次撞击声之间的时间间隔为10.0s。在相邻的平行车道上有另一列客
运列车乙，当旅客经过列车乙车头时，列车乙恰好从静止开始以恒定加速度沿列车甲行进的相
反方向启动。该旅客在此后的12.0s内，看到恰好有20节乙车的车厢（含车头在内）从他身旁
经过。已知每根铁轨的长度为25.0m，乙车车头及每节车厢的长度为26.5m，车厢间距忽略不计。
求：
（1）客车甲运行速度的大小；
（2）列车乙运行加速度的大小；
(1) V=37.5m/s；(2)a=
m/s2
题目分析:
（1）客车甲车做匀速运动，它的速度
5分
（2）12s内甲车运动的距离为 3分
令乙车的加速度为a，据位移公式知，12s内乙车运动的距离为：
3分
据题意知：
3分
解得：
| 任务型阅读：根据短文内容，将方框中的句子回填到短文中适当的位置。 | |
| Breakfast is the most important meal of the day! 1 You need some food to give you energy for the whole day. Any breakfast is better than no breakfast, but it's not a good idea to eat sweet food for breakfast all the time. 2 Try different kinds of foods: bread, cereal,meat, fruit, vegetables, eggs,milk… Some students don't eat breakfast because they get up late or because they think it's a good way to lose weight. 3 If you don't eat breakfast, you may feel tired when you're in class. 4 Next time if you get up late, don't forget to take some breakfast with you. Also, people who don't eat breakfast may eat more food during the day. 5 People should have a good breakfast to work well during the day.
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