气象研究小组用如图所示简易装置测定水平风速。在水平地面上竖直固定一根直杆,质量为m的空心塑料球用细线悬于杆顶端O,当水平风吹来时,球在水平风力的作用下飘起来。测得球平衡时细线与竖直方向的夹角θ=30°,(重力加速度为g,不考虑空气的浮力)则( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/4/1169e010-8c86-4cfe-8b72-8e6a9e2b9fbe.png?resizew=118)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/4/1169e010-8c86-4cfe-8b72-8e6a9e2b9fbe.png?resizew=118)
A.细线拉力大小为![]() | B.细线拉力大小为![]() |
C.细线拉力与风力的合力大于mg | D.风力大小F=![]() |
更新时间:2022-12-03 17:26:28
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