作业帮英文的理论力学题!the triangular plate ABC is supported by ball-and-socket joints at B and D and is held in the position shown by cables AE and CF.If the force exerted by cable AE at A is 220 lb,determine the moment of that force about the lin
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英文的理论力学题!the triangular plate ABC is supported by ball-and-socket joints at B and D and is held in the position shown by cables AE and CF.If the force exerted by cable AE at A is 220 lb,determine the moment of that force about the lin
英文的理论力学题!
the triangular plate ABC is supported by ball-and-socket joints at B and D and is held in the position shown by cables AE and CF.If the force exerted by cable AE at A is 220 lb,determine the moment of that force about the line joining points D and B
图有点不太清楚,原点到C点是36,原点到B点的距离36+12,B离“地面”的高度是14,D与A,C的水平距离均为16,（可能描述有错）请各位高手帮忙啊!我只有9分啊!只能给5分了!谢谢!
我大概懂了，是求DB上的力对应的力矩。那DB上力的矢量怎么求呢?DB上的力就是沿着DB(即作用于DB的力矢量与DB这条线重合)的吗?
英文的理论力学题!the triangular plate ABC is supported by ball-and-socket joints at B and D and is held in the position shown by cables AE and CF.If the force exerted by cable AE at A is 220 lb,determine the moment of that force about the lin
determine the moment of that force about the line joining points D and B..中的that force 应该是the force exerted by cable AE at A.所以啊.求的是AE这个力对DB连线的力矩..DB连线就是一根轴.
那么就是AE对DB轴的力矩.用矢量做.力矩就是M=r×F,然后将M分解为DB向和垂直与DB.M在DB向的分量就是要求的M(DB).
还有一种就是 AE与DB是异面直线,做一辅助平面P,n为AE×DB,是平面的法线方向,DB在平面P内.将AE分解为平行P和垂直于P,那么AE(平行)×距离（P与AE的）就是要求的力矩.
总的说来第一种简单些.即M= DB .（r×F）,DB的方向向量点乘（r叉乘AE力）,r是DB上任意一点到A点的方向向量,比如DA,或者BA.