16. A.
[tex]d = \frac{m}{V} \ \ \rightarrow \ \ m = d\cdot V[/tex]
17.
[tex]30\frac{kg}{m^{3}} = 30\cdot\frac{1000 \ g}{1000000 \ cm^{3}}=30\cdot\frac{1}{1000} \ \frac{g}{cm^{3}} = 0,03\frac{g}{cm^{3}}[/tex]
18.
[tex]V = 10 \ m^{3}\\d = 920\frac{kg}{m^{3}}\\m = ?\\\\m = d\cdot V=920\frac{kg}{m^{3}}\cdot10 \ m^{3}}\\\\\underline{m = 9 \ 200 \ kg}[/tex]
19.
[tex]m = 20 \ dag = 0,2 \ kg\\g = 10\frac{N}{kg}\\F = ?\\\\F = m\cdot g = 0,2 \ kg\cdot10\frac{N}{kg}\\\\\underline{F = 2 \ N}[/tex]
20.
[tex]m = 600 \ g\\d = 600\frac{kg}{m^{3}} = 0,6\frac{g}{cm^{3}}\\a = ?\\\\d = \frac{m}{V} \ \ \rightarrow \ \ V = \frac{m}{d}\\oraz\\V = a^{3}}\\\\a^{3} = \frac{m}{d}\\\\a^{3} = \frac{600 \ g}{0,6\frac{g}{cm^{3}}}=1000 \ cm^{3}\\\\a = \sqrt[3]{1000 \ cm^{3}}\\\\\underline{a = 10 \ cm}[/tex]
