沪杭铁路全线长约180千米，往来于沪杭两地间的动车组列车从上海至杭州用时约1.2小时，则该列车的平均速度约为______千米/小时．以路旁的树木为参照物，坐在车中的乘客是______的（选填“静止”或“运动”）． 列车在某一水平轨道上匀速前进时，列车的动能______（选填“减少”、“不变”或“增加”）．
由题意知：v=
=s t
=150km/h；180km 1.2h
以路旁的树木为参照物，坐在车中的乘客相对于树木的位置不断变化，则乘客是运动的；
一列车做匀速直线运动，质量不变，速度不变，故该列车的动能不变．
故答案为：150；运动；不变．
Nowadays green food is popular. We need green food and good health, not all people knew that well years ago. When I was in Grade Seven, my teacher asked us to something about green food by ourselves. We had no idea at first. Then our four-member group had a and went to do some research (调查) in a supermarket. Two of us wrote down the names of the food on the shelves. The other two customers (顾客) some questions like “Do you know what green food is?” “How often do you green food?” and so on. More than 30 customers our questions! Later each group in our class wrote a research report the topic and handed it in (交上). Our teacher chose the ones and put them up on the wall of the classroom. was one of them! We not only learned a lot about green food but also knew how to keep healthy.
|