问了好多人了 都没懂
问了好多人了 都没懂
问了好多人了 都没懂
问了好多人了 都没懂
首先你得记住:绕过轻滑轮的轻绳中张力处处相等.
所以重物对绳向下的拉力等于F1=mg,BC段绳的拉力也等于F2=mg,F1与F2成120度角,合力为滑轮受到绳子的作用力为F=mg=10*1)N=100N,C正确.
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it is too easy you shouldn't ask it for every i know someone named Didi may be she know what to do For the internet if you ues well it will benefit for you whatya want from it it depends yourself dfnsufo. good lucky
你可以沿细绳方向和其垂直方向建立直角坐标系,将重力正交分解。它只告诉你物体质量当然需要告诉你重力加速度才会让你求出重力啦
是100n吗?恩