Question

Latura unui cub de fag p1=750 kg/m³ este 5 cm.cât cântărește cubul daca are o cavitate vidata de volum V =25 cm³ ?

Answer 1

$\rho=\frac{m}{V}\\ \\ \Rightarrow m=\rho \cdot V\\ \\ V_{cub-total}=l^{3}=(5cm)^{3}=125cm^{3}\\ \\ V_{vid}=25cm^{3}\\ \\ V_{lemn-de-fag}=V_{cub-total}-V_{vid}\\ \\ V_{lemn-de-fag}=125cm^{3}-25cm^{3}=100cm^{3}=0,1dm^{3}=0,0001m^{3}\\ \\ m_{lemn-de-fag}= \frac{750kg}{m^{3}}\cdot 0,0001m^{3}=0,075kg=75g$