Wahadlo o dlugosci 99,5cm w ciagu 30s wykonalo 15 drgan. Ustal przyspieszenie swobodnego spadania.

[latex]T=2pi sqrt{frac{l}{a}} \ T=30s/15=2s \ T^2 = 4 pi^2 frac{l}{a} \ a = 4pi^2 frac{l}{T^2} = 0.995 pi^2 frac{m}{s^2}[/latex]