Question

un pendul cu lungimea de 2 m efectueaza timp de 1h 1268 de oscilatii. Determinati acceleratia caderii libere conform acestor date​

Answer 1

$l=2 \ m \\ t=1 \ h=3 \ 600 \ s \\ n=1 \ 268 \\ T=2\pi \sqrt{\frac{l}{\vec{g}}}=\frac{t}{n} \\ \Rightarrow \sqrt{\frac{l}{\vec{g}}}=\frac{T}{2\pi} \ \ \Rightarrow \frac{l}{\vec{g}}=(\frac{T}{2\pi})^2 \\ T=\frac{3 \ 600 \ s}{1 \ 268}\approx2,84 \ s \\ \Rightarrow \frac{l}{\vec{g}}=(\frac{2,84 \ s}{2 \cdot 3,14})^2\approx 0,204 \ s^2 \\ \Rightarrow \vec{g}=\frac{2\ m}{0,204 \ s^2} \\ \Rightarrow \boxed{\vec{g}=9,8 \ m/s^2}$