\( 8.0 ; 375 \mathrm{~g} / \mathrm{cm}^{3}=\ldots \mathrm{Mg} / \mathrm{nm}^{3} 3,75 x \) 9. \( 420 \mathrm{fm} . \mathrm{Mg}^{2} / \mathrm{s}^{2}=\ldots . \mathrm{Mm} . \mathrm{mg} / \mathrm{mnt}^{2} \)

To convert the given values, we need to understand the units involved and perform the necessary conversions. ### Problem 1: Convert \( 375 \, \text{g/cm}^3 \) to \( \text{Mg/nm}^3 \) 1. **Convert grams to megagrams (Mg)**: \[ 1 \, \text{Mg} = 10^6 \, \text{g} \] Therefore, \[ 375 \, \text{g} = \frac{375}{10^6} \, \text{Mg} = 3.75 \times 10^{-4} \, \text{Mg} \] 2. **Convert cubic centimeters to cubic nanometers**: \[ 1 \, \text{cm} = 10^7 \, \text{nm} \quad \Rightarrow \quad 1 \, \text{cm}^3 = (10^7 \, \text{nm})^3 = 10^{21} \, \text{nm}^3 \] 3. **Combine the conversions**: \[ 375 \, \text{g/cm}^3 = \frac{3.75 \times 10^{-4} \, \text{Mg}}{10^{21} \, \text{nm}^3} = 3.75 \times 10^{-25} \, \text{Mg/nm}^3 \] ### Problem 2: Convert \( 420 \, \text{fm} \cdot \text{Mg}^2/\text{s}^2 \) to \( \text{Mm} \cdot \text{mg}/\text{mnt}^2 \) 1. **Convert femtometers to megameters**: \[ 1 \, \text{fm} = 10^{-15} \, \text{m} \quad \Rightarrow \quad 1 \, \text{Mm} = 10^6 \, \text{m} \] Therefore, \[ 1 \, \text{fm} = 10^{-15} \, \text{m} = 10^{-15} \times 10^{-6} \, \text{Mm} = 10^{-21} \, \text{Mm} \] Thus, \[ 420 \, \text{fm} = 420 \times 10^{-21} \, \text{Mm} = 4.20 \times 10^{-19} \, \text{Mm} \] 2. **Convert megagrams to milligrams**: \[ 1 \, \text{Mg} = 10^6 \, \text{mg} \] Therefore, \[ \text{Mg}^2 = (10^6 \, \text{mg})^2 = 10^{12} \, \text{mg}^2 \] 3. **Convert seconds to minutes**: \[ 1 \, \text{s} = \frac{1}{60} \, \text{min} \quad \Rightarrow \quad 1 \, \text{s}^2 = \left(\frac{1}{60}\right)^2 \, \text{min}^2 = \frac{1}{3600} \, \text{min}^2 \] 4. **Combine the conversions**: \[ 420 \, \text{fm} \cdot \text{Mg}^2/\text{s}^2 = (4.20 \times 10^{-19} \, \text{Mm}) \cdot (10^{12} \, \text{mg}^2) \cdot \left(\frac{3600}{1}\right) \, \text{min}^2 \] \[ = 4.20 \times 10^{-19} \cdot 10^{12} \cdot 3600 \, \text{Mm} \cdot \text{mg}/\text{min}^2 \] \[ = 4.20 \times 3600 \times 10^{-7} \, \text{Mm} \cdot \text{mg}/\text{min}^2 \] \[ = 15120 \times 10^{-7} \, \text{Mm} \cdot \text{mg}/\text{min}^2 = 1.