d_{2} = \frac{ρ_{1} - ρ_{0}}{ρ_{0} - ρ_{2}} \cdot \frac{d_{1}}{2} = 9, 7 c m

${d_2 = \frac{\rho_1 - \rho_0}{\rho_0 - \rho_2}\cdot \frac{d_1}{2} = {9,7}{cm}\quad}$