Răspuns :
[tex]E_{elastica}=\frac{1}{2} \cdot k \cdot \Delta l^{2}\\
\\ \Rightarrow \Delta l^{2}=\frac{2 \cdot E_{elastica}}{k}\\
\\ \Delta l^{2}=\frac{2\cdot 14,4J}{2000N \div m}\\
\\ \Deltal^{2}=0,0144m^{2}\\
\\ \Delta l=\sqrt{0,0144m^{2}}=0,12m=12cm[/tex]
\\ \Rightarrow \Delta l^{2}=\frac{2 \cdot E_{elastica}}{k}\\
\\ \Delta l^{2}=\frac{2\cdot 14,4J}{2000N \div m}\\
\\ \Deltal^{2}=0,0144m^{2}\\
\\ \Delta l=\sqrt{0,0144m^{2}}=0,12m=12cm[/tex]