[tex]\frac{g}{cm^{3} } =\frac{\frac{1}{1000} }{(\frac{1}{100})^{3} } kg/m^{3} =\frac{\frac{1}{1000} }{\frac{1}{1000000} } kg/m^{3} =\frac{1}{1000} :\frac{1}{1000000} kg/m^{3}=\frac{1}{1000}*1000000kg/m^{3}= 1000kg/m^{3}[/tex]
1. 7,8 g/cm^3= 7,8 * 1000 kg/m^3= 7800 kg/m^3
2. 10,8 g/cm^3 = 10800 kg/m^3
3. gęstość = 280/32,8=8,5 g/cm^3 = 8500 kg/m^3
4. gęstość = 90/32,8 = 2,7 g/cm^3 = 2700 kg/m^3
