Se da:
[tex]p=7800\frac{kg}{m^{3}}\\
v=20\frac{m}{s}\\
Ec=1560J\\
l=?m\\
Formule:\\
Ec=\frac{m*v^{2}}{2}\\
m=\frac{Ec*2}{v^{2}}\\
p*V=\frac{Ec*2}{v^{2}}\\
l^{3}=\frac{Ec*2}{v^{2}*p}\\
l=\sqrt[3]{\frac{Ec*2}{v^{2}*p}} \\
Calcule:\\
l=\sqrt[3]{\frac{1560*2}{20^{2}*7800}}=0,1m
[/tex]