力的图示是初二物理中分析和解决物理问题的基本方法。很多同学在初学时，容易犯一些错误。下面通过例题加以辨析。例１用５０N的力F竖直向上提箱子。分析尽管在图中标明了力的作用点、力的大小和方向，但遗漏了比例标度。应补画上比例标度，即一格代表１０N的力。例２用竖直向 The graphical representation of force is the basic method for analyzing and solving physical problems in the second day of physics. Many students are prone to making mistakes when they are learning. The following examples are used to distinguish. Example 1 Lifts the box upright with 50N force F. Analysis Although the point of application of the force, the magnitude and direction of the force are indicated in the figure, the scale of the scale is omitted. The proportion scale should be added, that is, one grid represents 10N force. Example 2 with vertical