2. A horizontal force of 10 N pushes a 0.5-kg block against a vertical wall. The book is initially at rest. If the static coefficient of friction (μs) is 0.6 and the kinetic coefficient of friction (μk) is 0.4, which of the following is true?
(A) The frictional force is 4.9 N
(B) The frictional force is 6.0 N
(C) The frictional force is 4.0 N
(D) The normal force is 4.9 N
(E) The normal force is 10.9 N.
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統計: A(0), B(0), C(0), D(1), E(0) #3221221
統計: A(0), B(0), C(0), D(1), E(0) #3221221
詳解 (共 2 筆)
#7402668
所以如果把東西壓在牆上
第一步先算重力,為4.9N
最大靜摩擦力為6N
然後比較大小
如果重力小於極限(沒掉下來)
重力會等於摩擦力
重力大於極限,摩擦力會等於推力乘以動摩擦係數
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