半圆形铁圈的重心在什么位置

具体一点的位置 有图就更好了
2025-04-08 10:37:06
推荐回答(3个)
回答1:

给你一个具体的方法
高中物理竞赛中讲到一个定理叫巴普斯定理,内容如下:
在一平面上取任一闭合区域,使它沿垂直于该区域的平面运动形成一个立体,那么这个立体图形的体积就等于质心所经路程乘以区域面积。
于是运用上述定理求解
把半圆形铁圈的直径用同种材料的铁材料补全,该闭合区域绕直径旋转一周形成的球体,体积等于重心所经路程乘以区域面积
设半圆环半径为r,则半圆面积为1/2*π*r^2
设合系统的重心距离圆心的距离为x
(1/2*π*r^2)*(2πx)=4/3*π*r^3
x=(4r)/(3π)
又直径的铁线的重心与圆心重合,在根据力矩平衡有
mg*(4r)/(3π)=π/(2r)mg*(d-(4r)/(3π))
求解d即可,得到的就是重心的位置

回答2:

在那个半圆构成面积的几何中心,没在圈上

回答3:

圆形的圆心上去一点
想象一下悬挂法测重心就知道了

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