论文部分内容阅读
静力学问题中,经常遇到有关静摩擦力的问题,因为静摩擦力的大小和方向很难确定,故解题时往往要分几种情况进行讨论,解题过程比较繁琐。如果用绝对值不等式解这类问题,就显得特别简捷,现举几例如下。 例1.如图1所示,斜面的倾角θ=30°,斜面上的物体A重10牛顿,物体A和斜面的静摩擦系数为μ_0=0.4,为使物体A静止在斜面上,定滑轮所吊物体B的重力应为多大?(绳与滑轮间无摩擦,绳子的重力不计)
In the statics problem, the problem of static friction is often encountered because the magnitude and direction of static friction are difficult to determine. Therefore, when solving a problem, it is often necessary to discuss the situation in several situations, and the problem-solving process is cumbersome. If you use the absolute value inequality to solve such problems, it is particularly simple and straightforward. Example 1. As shown in Fig. 1, the inclination angle of the inclined surface is θ = 30°. The object A on the inclined surface weighs 10 newtons. The static friction coefficient of the object A and the inclined surface is μ_0 = 0.4. To make the object A stand still on the inclined surface, the pulley is fixed. What is the weight of the object B? (No friction between the rope and the pulley, the weight of the rope does not count)