Hello, I'm moon, yesterday we did a experiment about a pendulum, we needed to figured out how did pendulum go not fast and not slow when we made the string longer in 30s.

First, we took some goal to make a pendulum for our experiment ( the length of the string, some size of the swing and the weight of the bob) .

then, we drew some lines on the string, we needed those lines to tell we how long was there ( 10cm, 20cm, 30cm, 40cm and 50cm ) .

At last, we found the answer, when we made the string longer the pendulum will went slow.