7、 一簡支樑受集中力作用如下圖所示，其最大撓曲點在下列何處？&nbsp;<div><img src="https://img.yamol.tw/item/873346-0-5eb807c7600a2.png#s-441,115"></div><div>(A) 0 &lt; x &lt; L/3 (B) x = L/3 (C) L/3 &lt; x &lt; 2L/5 (D) 2L/5 &lt; x &lt; L </div>

10、 In Figure 10, a horizontal force of 500 N acts on a block of weight 1.5 kN placed on an inclined plane. The coefficients of friction between the block and the plane are μs =0.25 andμk = 0.20 . What is the actual frictional force? (A) 200N (B) 500 N (C) 300 N (D) 450 N。