k=1mg\mathrm{k}=\dfrac{1}{\mathrm{mg}}k=mg1
k=mgℓ\mathrm{k}=\dfrac{\mathrm{mg}}{\ell}k=ℓmg
k=m2 g1k=\dfrac{m^{2} \mathrm{~g}}{1}k=1m2 g
k=1mg2k=\dfrac{1}{m g^{2}}k=mg21