[tex]\bold{constanta \ elastic\u{a}:} \ k=\frac{F_e}{\Delta l} \\ \bold{forta \ elastic\u{a}:} \ F_e=k \cdot \Delta l \\ \bold{de formarea \ elastic\u{a}:} \ \Delta l=\frac{F_e}{k}=l_2-l_1 \\ \bold{forta \ de \ greutate \ (ponderea):} \ G=m \cdot g , \ unde \ m \to masa, \ iar \\ g \to acceleratia \ gravitational\u{a} \ g=9,8 \ N/kg; \\ \bold{forta \ de \ frecare:} \ F_f=N \cdot \mu, \ unde \ N \to forta \ normala \ de \ greutate, \ iar \\ \mu \to coeficientul \ de \ frecare[/tex]
