在实际的教学工作中,有的教师在对前一章《曲线运动》进行了完美的教学后,顺理成章地进入到《万有引力与航天》这一章,并直接把结论告诉学生:中心天体M对绕行天体m的引力充当了天体m做匀速圆周运动所需要的向心力……让人觉得把《万有引力与航天》单独编排为一章完全没必要,只要把它当做圆周运动问题的一个“特例”就可以了。笔者前些年也是这样想的,但之后发现:经典的“日──地”模型在地球引力问题上总有一 In the actual teaching work, after some teachers have perfect teaching on the “Curvilinear Movement” in the previous chapter, they go straight to the chapter of “Gravitation and Aerospace” and directly tell the students the conclusion that the central object M The gravitational force of the detour celestial body m serves as the centripetal force required by celestial body m to make a constant circular motion ... It is totally unnecessary to arrange “gravitational and aerospace” as a separate chapter, as long as it is treated as a special case of circular motion “On it. The author also thought a few years ago, but later discovered that the classic ”day-to-earth" model always had a