It's like a pendulum which has a length of 115 meters.

就像一个钟摆，长度115米。

youdao

Using the single pendulum, we can research the relationship between the period of oscillation of it and the length of it and measure local acceleration of gravity.

通过单摆装置可以方便地研究单摆的振动周期与摆长关系和测定当地的重力加速度。

youdao

So in experiment we should measure the length of single pendulum, then get the period of oscillation in this condition.

在实验中就要测定单摆的摆长，然后测定此摆长时的振动周期。

youdao

This is how he adjusts the time by changing the length of the pendulum.

UNESCO: Culture