O sa consider ca suntem in conditii de izocronism.
[tex]1. T=2\pi \sqrt{\dfrac{l}{g}}\\T=2\cdot \sqrt{\pi^2\cdot \dfrac{1}{g}}\\\text{Putem simplifica }\pi^2 \text{ cu }g.\\T=2\sqrt 1= 2 s\\\nu =\dfrac{1}{T}\\\nu = \dfrac{1}{2}= 0,5\ Hz[/tex]
[tex]2. T=\dfrac{1}{\nu }\\T=\dfrac{1}{4} =0,25 s\\T=2\cdot \pi \sqrt{\dfrac{l}{g}}|()^2\\T^2=4\pi^2 \cdot \dfrac{l}{g}\\\text{Din nou putem simplifica }\pi^2 \text{ cu }g.\\T^2=4l\\l=\dfrac{T^2}{4}\\l=\dfrac{0,0625}{4}=0,015625 m[/tex]