解决内轨道习题时的难点是:对临界条件的理解出现偏差,导致解题错误。该知识点常与平抛运动、类平抛运动、动能定理综合起来考察。在多年的教学中,我就自己的经验做出以下诠释。例如,如图所示,竖直平面内有一个半径为R的半圆形轨道OQP,其中Q是半圆形轨道的中点,半圆形轨道与水平轨道OE在O点相切,质量为m的小球沿水平轨道运动,通过O点进入半圆形轨道,恰好能够通过最高点P,然后落到水平轨道上,不计一切 The difficulty in solving internal track exercises is that deviations in the understanding of critical conditions cause errors in solving problems. This knowledge is often combined with Ping-Ping movement, Ping-Ping movement, and kinetic energy theorem. In many years of teaching, I have made the following interpretation of my own experience. For example, as shown in the figure, there is a semi-circular orbit OQP with a radius R in the vertical plane, where Q is the midpoint of the semicircular orbit, and the semicircular orbit is tangent to the horizontal orbit OE at point O. The mass is The ball of m moves along a horizontal track and enters a semi-circular orbit through point O. It can just pass through the highest point P and then fall onto a horizontal track, irrespective of everything