论文部分内容阅读
一、正确理解基本概念1.力 力是物体间的相互作用.这是力的定义,要正确理解它,就不单是要熟记这几个字,更应理解它的确切内涵和外延,必须掌握它的性质以及几种常见力的特点、方向的判断.①力的性质:力的作用是相互的.当一个物体受到力的作用,则必定有另一个物体来产生这一作用力.同时,被作用的物体也会产生一个大小相等、方向相反的反作用力去作用于另一物体,这个力就是反作用力.作用力与反作用力不仅大小相等、方向相反,而且是同时产生,同时消失的,大小、方向和作用点是描述力的三个要素.②常见力及方向:重力是地球对物体的吸引而产生的力,它的方向始终竖直向下而指向地心;弹力是物体因形变而产生的力,它的方向是沿接触面法线且与形变趋势相反的方向,平时所说的压力、支持力也属弹力的范畴.弹力方向的判断通常是受力分析的关键,如
First, the correct understanding of the basic concepts 1. Force is the interaction between objects. This is the definition of force, to correctly understand it, it is not only to memorize these words, but also to understand its exact connotation and extension, must Grasp its nature and the judgment of the characteristics and direction of several common forces. 1 The nature of force: The role of force is mutual. When an object is subjected to a force, there must be another object to produce this force. The affected object will also produce an equal and opposite reaction force acting on another object. This force is the reaction force. The force and reaction force are not only equal but opposite in direction, and they are produced simultaneously and disappear at the same time. The size, direction, and point of action are three elements that describe force. 2 Common Forces and Directions: Gravity is the force generated by the earth’s attraction to an object. Its direction is always vertical and points downward to the center of the earth; elasticity is the cause of an object. The force generated by the deformation, its direction is along the normal to the contact surface and the direction opposite to the deformation trend, usually speaking the pressure, support force is also a category of elasticity. The direction of the elastic force is usually the key to force analysis.