The point: that a period of a pendulum is independent of the mass - the steel ball, plus one professor - hanging from it.

目的是证明：钟摆周期和质量无关—那个铁球的，以及挂在上面的那个物理教授的。

youdao

To state the restoring force of a simple pendulum during oscillation is the resultant force of the gravity of the ball and the pulling force of the thread is wrong .

常出现一些模糊认识，即认为单摆在振动中所受的回复力就是摆球所受重力与绳子拉力的合力，显然，这是错误的。

youdao

The inflation driven exhilaration proves fleeting as the pendulum swings back like a wrecking ball.

FORBES: You Call It Inflation, I Call It Theft