物理概念和物理量历来是物理教学中的重点和难点.为什么物理概念和物理量难教难学?原因是多方面的.笔者想对出现在初中物理中的一类物理概念的操作定义(即物理量)谈谈自己的看法,以求同行们的斧正。密度是不是质量?压强是不是压力?比热是不是热量?……对这些问题的回答当然是否定的.但是,初中学生刚刚接触“密度”、“压强”、“比热”等概念时.往往分别和“质量”、“压力”、“热量”等概念混淆.如在“压强”这一章中,认为拖拉机履带的作用是增大面积以减少对地面的压力;又认为两个截面积不同的圆柱形容器中盛有同样高度的水对底面的压强是不一样的,原因是两个容器中的水的重量不一样,如此 Physical concepts and physical quantities have traditionally been the focus and difficulty in physics teaching. Why are physical concepts and physical quantities difficult to learn? The reasons are manifold. The author wants to define the operational concepts of a class of physical concepts that appear in junior high school physics (ie physical quantities). Talk about your own views, in order to seek the axe of your colleagues. Is density a quality? Pressure is not stress? Is specific heat a calorie?... The answer to these questions is of course negative. However, junior high school students have just come into contact with concepts such as “density”, “pressure” and “specific heat”. Often confused with concepts such as “quality,” “stress,” and “heat.” As in the chapter “Pressure,” the role of tractor tracks is to increase the area to reduce pressure on the ground; two cross-sectional areas are also considered. Different cylindrical containers contain the same height of water and the pressure on the bottom surface is different because the weight of the water in the two containers is not the same.