小学科学四年级下册2运动的快慢PPT课件

In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
一.比较物体运动快慢的方法:
1.相同距离比时间 2.相同时间比距离
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
测一测走路的速度
活动：记录一段时间，测所走距离。
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
测量记录表
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
● 刘翔以12秒91的获得冠军
●
美国选手特拉梅尔以 13秒18获得亚军
● 古巴选手加西亚以13秒20 的成绩获得第三名
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
课后活动：
利用手表计时，在操场上测量步 行一周需要多长时间，根据绕操场 一周行走的距离计算你的步行速度。
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
小明行走的速度： 5 千米 / 小时。 读作： 5千米每小时
表示：小明1小时通过的距离是5千米。
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
同学1 同学2
距离
米 米
时间
秒 秒
速度
米/秒 米/秒
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have bee
1 3 7 4
6 5 2 8
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
运动快慢
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
刘翔参加的什 么竞赛项目
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious
新问题：
若距离不相同，时间也不相同时，那
如何去比较运动的快慢呢？
运动 物体
兔子 抹香鲸
台风
通过的 距离
56千米 66千米 60千米
所用 1小时 时间 通过的距离 1小时 56千米 3小时 22千米 2小时 30千米
运动的快慢可以用单位时间内通过的 距离来测量，这就是常说的运动的速度。
In this academic year, I have served as a political subject in three classes at Grade 2. A school year, I have been serious