[tex]Dane:\\V = 64 \ cm^{3} =0,000064 \ m^{3}\\d = 0,8\frac{g}{cm^{3}} = 800\frac{kg}{m^{3}}\\g = 10\frac{N}{kg}\\Szukane:\\F_{w} = ?\\\\\\F_{w}=d\cdot g\cdot V\\\\F_{w} = 800\frac{kg}{m^{3}}\cdot10\frac{N}{kg}\cdot0,000064 \ m^{3}\\\\\boxed{F_{w} = 0,512 \ N}[/tex]