Ipoteza:
ρ=800 Kg/m³
l=10 cm
K=100 N/m
Δl=?
Rezolvare:
V cub=l³=10 cm³=1000 cm³=0.001 m³
ρ=m/V
800 Kg/m³=m/0.001 m³
m=800 Kg/m³×0.001 m³=0.8 Kg
consideram g≈9,8 N/Kg
G=m×g=0.8 Kg×9,8 N/Kg=7.84 N
Fe=G⇒Fe=7.84 N
Fe=K×Δl
7.84 N=100 N/m×Δl
Δl=7.84 N/100 N/m=0.0784 m
Succes!
