Question

o bara de aluminiu cu dimensiunilede 10,4,2cm a intins un resort cu 10 cm.Afla constanta de elasticitate

Answer 1

$a=10 \ cm=0,1 \ m \\ b=4 \ cm=0,04 \ m \\ c=2 \ cm=0,02 \ m \\ \triangle l=10 \ cm=0,1 \ m \\ g=10 \ N/kg \\ \rho=2700 \ kg/m^3 \\ \boxed{k-?}\bold{Rezolvare:} \\ \boxed{k= \frac{F_e}{\triangle l} } \\ \boxed{F_e=G=m \cdot g} \\ \boxed{\rho= \frac{m}{V} } \\ \boxed{V=a \cdot b \cdot c } \\ V=0,1 \ m \cdot 0,04 \ m \cdot 0,02 \ m \\ V=0,00008 \ m^3 \\ m=\rho \cdot V \\ m=2700 \ kg/m^3 \cdot 0,00008 \ m^3 \\ m=0,216 \ kg \\ F_e=G=0,216 \ kg \cdot 10 \ N/kg \\ F_e=2,16 \ N \\ k= \frac{2,16 \ N}{0,1 \ m}$
$\Rightarrow \boxed{k=21,6 \ N/m}.$