题如图1,小球质量为m,沿光滑的斜轨道由静止滑下.圆形轨道半径为R.要使小球沿光滑圆轨道恰能通过最高点.问小球应从斜轨道上何处开始滑下?解设小球从斜轨道上距最低点h高处滑下,取最低点为零势点,则所以h=-5/2R.这是一道很常见的题.如果小球放得再低点,情况 The problem is shown in Fig. 1. The mass of the ball is m, and it slides down from a standstill along a smooth oblique orbit. The radius of the circular orbit is R. It is necessary for the ball to pass the highest point along a smooth circular orbit. What should the ball be from the inclined orbit? At the beginning of the slide, the solution ball slides down from the high point of the lowest point h on the oblique track, and the lowest point is the zero potential point, so h=-5/2R. This is a very common question. If the ball Put it low again, the situation