惯性定律和惯性是初二物理的重要知识，它们有着本质的区别，但有些同学常常把它们混为一谈．为了解决这一问题，现谈谈惯性定律和惯性的区别及联系．惯性定律（牛顿第一定律）是物理规律，反映的是物体运动的规律，它的内容是：一切物体在没有受到外力作用的时候，总保持静止 Inertia law and inertia are the important knowledge of the second day physics, they have the essential difference, but some classmates often confuse them. In order to solve this problem, we now talk about the difference and connection between inertia law and inertia. The Law of Inertia (Newton’s first law) is a physical law that reflects the law of motion of an object. Its content is that all objects always remain stationary when they are not subjected to an external force.