本刊1997年第10期严俊同志所写《用加速度求解单摆的周期公式》一文中,对g的理解是:“在确定的物理条件下,摆球在平衡位置未受扰动时绳子张力所产生的加速度a’,则有T=2π(l/a’)~(1/2)就可求出单摆的振动周期”.文中所举例的求解是无可非疑的,问题是用单摆周期公式T=2π(l/a’)~(1/2)求周期时,确定的物理条件到底指什么是不明确的.笔者在此作一理论上的分析,否则容易造成死套结论,造成教学上的思维定势. Comrade Yan Jun wrote in his article “The Periodic Formula for Solving a Single Pendulum with Acceleration”, the understanding of g is: “In a certain physical condition, the rope swings when the pendulum ball is not disturbed at the equilibrium position. The resulting acceleration a’, then T=2π(l/a’)~(1/2) can be used to find the oscillation period of a single pendulum. The solution in the paper is unquestionable. The problem is that When the single pendulum periodic formula T=2π(l/a’)~(1/2) finds the period, it is unclear what the determined physical conditions mean. The author makes a theoretical analysis here, otherwise it is easy to cause deadlock. In conclusion, the thinking in teaching is fixed.