\( \left. \begin{array} { l } { 420 fm \cdot Mg / s ^ { 2 } = \ldots \ldots km \cdot mg / mnt ^ { 2 } } \\ { 0 \cdot 0,685 kg / m ^ { 3 } = \cdots g / mm ^ { 3 } } \end{array} \right. \)

To convert the given units, we will handle each equation separately. ### 1. Conversion of \( 420 \, \text{fm} \cdot \text{Mg/s}^2 \) to \( \text{km} \cdot \text{mg/mnt}^2 \) **Step 1: Convert femtometers (fm) to kilometers (km)** 1 fm = \( 10^{-15} \) m 1 km = \( 10^3 \) m Thus, \[ 1 \, \text{fm} = 10^{-15} \, \text{m} = 10^{-15} \, \text{m} \cdot \frac{1 \, \text{km}}{10^3 \, \text{m}} = 10^{-18} \, \text{km} \] So, \[ 420 \, \text{fm} = 420 \times 10^{-18} \, \text{km} = 4.2 \times 10^{-16} \, \text{km} \] **Step 2: Convert Megagrams (Mg) to milligrams (mg)** 1 Mg = \( 10^6 \) g 1 g = \( 10^3 \) mg Thus, \[ 1 \, \text{Mg} = 10^6 \, \text{g} = 10^6 \times 10^3 \, \text{mg} = 10^9 \, \text{mg} \] So, \[ 420 \, \text{Mg} = 420 \times 10^9 \, \text{mg} = 4.2 \times 10^{11} \, \text{mg} \] **Step 3: Convert seconds (s) to minutes (mnt)** 1 minute = 60 seconds, so \[ 1 \, \text{s} = \frac{1}{60} \, \text{mnt} \] Thus, \[ 1 \, \text{s}^2 = \left(\frac{1}{60}\right)^2 \, \text{mnt}^2 = \frac{1}{3600} \, \text{mnt}^2 \] **Step 4: Combine the conversions** Now we can combine everything: \[ 420 \, \text{fm} \cdot \frac{420 \, \text{Mg}}{1 \, \text{s}^2} = (4.2 \times 10^{-16} \, \text{km}) \cdot \left(4.2 \times 10^{11} \, \text{mg}\right) \cdot \left(3600 \, \text{mnt}^2\right) \] Calculating this gives: \[ = 4.2 \times 10^{-16} \cdot 4.2 \times 10^{11} \cdot 3600 \, \text{km} \cdot \text{mg/mnt}^2 \] \[ = 4.2 \cdot 4.2 \cdot 3600 \times 10^{-16 + 11} \, \text{km} \cdot \text{mg/mnt}^2 \] \[ = 4.2 \cdot 4.2 \cdot 3600 \times 10^{-5} \, \text{km} \cdot \text{mg/mnt}^2 \] Calculating \( 4.2 \cdot 4.2 \cdot 3600 \): \[ = 17.64 \cdot 3600 \approx 63504 \] Thus, we have: \[ = 63504 \times 10^{-5} \, \text{km} \cdot \text{mg/mnt}^2 = 6.3504 \, \text{km} \cdot \text{mg/mnt}^2 \] ### 2. Conversion of \( 0.685 \, \text{kg/m}^3 \) to \( \text{g/mm}^3 \) **Step 1: Convert kilograms (kg) to grams (g)** 1 kg = \( 1000 \, \text{g} \) So, \[ 0.685 \, \text{kg} = 0.685 \times 1000 \, \text{g} = 685 \, \text{g} \] **Step 2: Convert cubic meters (m