考测点导航知道牛顿第一运动定律:一切物体在没有受到外力作用的时候,总保持匀速直线运动状态或静止状态。这个定律通常又叫做惯性定律。知道把物体保持静止或匀速直线运动状态的性质叫做惯性,惯性是一切物体的固有属性。掌握二力平衡的条件:作用在同物体上的两个力,必须大小相等、方向相反,并作用在同一直线上。理解物体受平衡力作用时,总保持匀速直线运动状态或静止 The test point navigation knows Newton’s first law of motion: when all objects are not subjected to external forces, they always maintain a uniform linear motion state or a static state. This law is often called inertial law. The property of knowing to keep an object stationary or in a state of uniform linear motion is called inertia. Inertia is an intrinsic property of all objects. Grasp the condition of the two-force balance: the two forces acting on the same object must be equal in magnitude and opposite in direction and act on the same line. Understand that when an object is acted on by a counterbalancing force, it always maintains a uniform linear motion or is stationary