| Difficulty | Secondary School | High school/other |
| ★ | Basic | Easy |
| ★★ | Demanding | Basic |
| ★★★ | Demanding | |
| ★★★★ | Difficult | |
| ★★★★★ | Very difficult |
Investigate the effect of the pendulum length on the oscillation time. Present the results graphically and determine from the graphical representation of the pendulum length when the oscillation time is 1 sec.
Answer: 0,25 - 0,26 m