名校
1 . 为了测量灯塔
的高度,第一次在
点测得
,然后向前走了20米到达点
处测得
,点
、
、
在同一直线上,则灯塔
高度为( )米
![](https://img.xkw.com/dksih/QBM/2021/11/22/2856852047282176/2860518338109440/STEM/c1cf27df84794868b19a14f7f00237a3.png?resizew=175)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392b9e1a179a6676362679354a9e7e51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a690535ef8766d108cce93b9e8544311.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2021/11/22/2856852047282176/2860518338109440/STEM/c1cf27df84794868b19a14f7f00237a3.png?resizew=175)
A.10 | B.![]() | C.![]() | D.![]() |
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名校
解题方法
2 . 如图,在平面直角坐标系
中,质点
间隔3分钟先后从点
出发,绕原点按逆时针方向作角速度为
弧度/分钟的匀速圆周运动,则
与
的纵坐标之差第5次达到最大值时,
运动的时间为_________ 分钟.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://img.xkw.com/dksih/QBM/2021/11/18/2854050105245696/2860558071930880/STEM/49b59a8b0ce34d00badf97a471f72d20.png?resizew=130)
您最近一年使用:0次
名校
解题方法
3 . 一个玩具盘由一个直径为
米的半圆
和一个矩形
构成,
米,如图所示.小球从
点出发以
的速度沿半圆
轨道滚到某点
处后,以
的速度沿与点
切线垂直的方向弹射到落袋区
内,落点记为
.记
,
![](https://img.xkw.com/dksih/QBM/2020/11/17/2595116550930432/2596337011105792/STEM/67f1c7fffe434f32a8a63943a3d07200.png?resizew=156)
(1)用
表示小球从
到
所用的时间
;
(2)当小球从
到
所用的时间最短时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14328c04e5524c830f344568f866e754.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4fbb013c2908593f5e7fa76c65e5482.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f5a953038f38cce86187f1619f6876.png)
![](https://img.xkw.com/dksih/QBM/2020/11/17/2595116550930432/2596337011105792/STEM/67f1c7fffe434f32a8a63943a3d07200.png?resizew=156)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd288d4152caf5fc8187a1a901c8949f.png)
(2)当小球从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
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