施工员小丁手持电钻从梯子爬上顶面施工,当爬到梯子顶端时,梯子突然滑倒,从3m高处跌下,被砸成重伤,这个教训让他能记一辈子。梯子为什么会突然滑倒呢?这得从力的平衡原理进行分析。如图1所示,设梯子的自重为P,上端靠在光滑的墙上,下端放在粗糙的地板上,梯子与地板的摩擦系数为f Xiaodian handheld electric drill construction workers climbing up from the ladder construction, when climbing to the top of the ladder, the ladder suddenly slipped, falling from 3m height, was smashed into serious injuries, this lesson allows him to remember forever. Why did the ladder suddenly slip? This has to be analyzed from the principle of balance of forces. As shown in Figure 1, set the ladder’s weight P, the upper end against a smooth wall, the bottom on the rough floor, the friction coefficient between the ladder and the floor f