Question

V= 1l
p ulei = 800 kg / m la puterea 3
....... m= ?

Answer 1

V = 1l = $10^{-3} m^{3}$
p = m/V => m = p*V => p=800*$10^{-3}$ = 0.8 kg

Answer 2

$V=1 \ l=1 \ dm^3=0,001 \ m^3 \\ \rho=800 \ kg/m^3 \\ \boxed{m-?} \\ \bold{Rezlvare:} \\ \boxed{\rho=\frac{m}{V} } \\ \Rightarrow m=\rho \cdot V\\ m=800 \ kg/m^3 \cdot 0,001 \ m^3 \\ \Rightarrow \boxed{m=0,8 \ kg}.$