問題詳情
19.一雙線螺紋之螺旋起重機，節距為5mm，作用臂長20cm，若摩擦損失為50%，則需施力若干方能舉起3140N之重物？
(A)50N
(B)63N
(C)75N
(D)200N。
(A)50N
(B)63N
(C)75N
(D)200N。
參考答案
無參考答案
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