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在日常生活中,常可见到人们将梯子斜靠在墙上,然后登梯进行工作,有时也可见到由于梯子靠墙过斜或地面对梯子的摩擦力过小致使人登至梯子中途而梯子即行滑倒地面摔伤人的情形。梯子为什么会滑倒?何时开始滑动?要求人登至梯顶而梯子仍不会滑动的条件是什么?这些都是力的平衡问题。下面对此加以分析:设:人的质量为 m,梯子的质量为 m_1,梯长为 l,其质心在梯子中点,地面对梯子的静摩擦力为 f、静摩擦系数为μ,地面对梯子的支持力为 N,光滑墙对梯子的作用力为 N_1,梯
In daily life, people can often see the ladder leaning against the wall, and then climb the ladder to work. Sometimes it can be seen that the ladder is leaning against the wall or the friction force on the surface is too small, causing people to climb to the middle of the ladder. The ladder will fall on the ground and fall. Why are the ladders slipping? When do they start to slide? What are the conditions that require people to climb to the top of the ladder and the ladder still does not slide? These are the balance of forces. This is analyzed as follows: Design: The mass of the person is m, the mass of the ladder is m_1, the length of the ladder is l, the center of mass of the ladder is midpoint of the ladder, the static friction force of the surface to the ladder is f, the static friction coefficient is μ, the ground The support for the ladder is N, and the force of the smooth wall on the ladder is N_1.