如图,某大风车的半径为2米,每12秒沿逆时针方向旋转一周,它的最底点O离地面1米,风车圆周上一点A从最底点O开始,运动t秒后与地面距离为h米,
(1)求函数h=f(t)的关系式,并在给出的方格纸上用五点作图法作出h=f(t)在一个周期内的图象(要列表,描点).
(2)A从最底点O开始,沿逆时针方向旋转第一周内,有多长时间离地面的高度超过4米?
考点分析:
相关试题推荐
设
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/2.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/3.png)
∥
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/4.png)
,试求满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/5.png)
的
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611018_ST/6.png)
的坐标(O为坐标原点).
查看答案
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/images0.png)
如图,平面内有三个向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/2.png)
,其中
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/3.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/4.png)
的夹角为120°,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/5.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/6.png)
的夹角为30°.且|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/7.png)
|=1,|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/8.png)
|=1,|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/9.png)
|=2
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/10.png)
,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/11.png)
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/12.png)
+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611017_ST/13.png)
,求λ+μ的值.
查看答案
一条河的两岸平行,河的宽度为480m,一艘船从某岸的A处出发到河对岸,已知船的速度
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/0.png)
,水流的速度
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/1.png)
,当行驶航程最短时,所用的时间是
min,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/2.png)
=(2,1),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/3.png)
=(3,4),则向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/4.png)
在向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611016_ST/5.png)
方向上的投影为
.
查看答案
若△ABC的三边的中点坐标为(2,1)、(-3,4)、(-1,-1),则△ABC的重心坐标为
.
查看答案
函数y=2sin(ωx+φ),|φ|<
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222906681161153/SYS201311012229066811611014_ST/0.png)
的图象如图所示,则ω=
,φ=
查看答案