内容正文:
鲁科版2019物理必修一
1.2质点和位移
Life is not about waiting for the storm to pass, its about learning to dance.
导入新课
观看: 嫦娥奔月
思考:
描绘卫星运行轨迹时,是否需要考虑卫星的形状?
卫星进行速率阻尼,调增姿态时,是否考虑卫星的形状呢?
Life is not about waiting for the storm to pass, its about learning to dance.
2
思考:
描绘卫星运行轨迹时,是否需要考虑卫星的形状?
描绘卫星卫星调增姿态,对准太阳,打开电池板时,又是否需要考虑卫星的形状呢?
1.质点
Life is not about waiting for the storm to pass, its about learning to dance.
3
1.质点
1、定义:用来代替物体的有质量的点。
2、条件:物体的形状、大小在所研究问题中可以被忽略。
3、科学思维:理想化的“模型”,质点不是真实的物体。(抓住主要因素,忽略次要因素。)
4、对质点的理解:大小和形状是否可忽略?
梳理深化:
Life is not about waiting for the storm to pass, its about learning to dance.
4
小试牛刀
分析研究下列物体运动时,研究对象能看作质点的是( )
A.研究“嫦娥三号”奔月的过程
B.研究奥运冠军邓琳琳在平衡木上的动作
C.研究从斜面上滑下的木块的滑行时间
D.研究运动员发出的弧旋乒乓球的旋转情况
Life is not about waiting for the storm to pass, its about learning to dance.
5
Life is not about waiting for the storm to pass, its about learning to dance.
6
2. 位移
交流讨论:
Life is not about waiting for the storm to pass, its about learning to dance.
7
2.位移
一位同学从操场中心A出发,向东走了40 m,到达B点,然后又向北