Răspuns:
p=800 kg/m3a=8 cm=0,08 mΔl1=8 cm=0,08 mΔl2=2 cm=0,02 mg=10 m/s2a) k=ΔlFe; Fe=G=m⋅g;ρ=Vm ⇒m=ρ⋅V;V=a3=(0,08 m)2=0,000 512 m3⇒m=800 kg/m3⋅0,000 512 m3=0,409 6 kg⇒Fe=G=0,409 6 kg⋅10 N/kg=4,096 N⇒ k=0,08 m4,096 N=51,2 N/m
Ff=k⋅Δl2=51,2 N/m⋅0,02 m=1,024 N⇒GFf=4,096 N1,024 N=0,25