Question

Știți cum se rezolva ?

Answer 1

[tex]\displaystyle Se~da:\\ \\ V_1=200ml=0,0002m^3\\ \\ V_2=50cm^3=0,00005m^3\\ \\ \rho_1=1\frac g{cm^3}=1000\frac {kg}{m^3}\\ \\ \rho_2=0,9\frac g{cm^3}=900\frac{kg}{m^3}\\ \\ \rho=?\frac {kg}{m^3}\\ \\ \\[/tex]


[tex]\displaystyle Formule:\\ \\ \rho=\frac mV\\ \\ \rho=\frac{m_1+m_2}{V_1+V_2}\\ \\ \rho=\frac{\rho_1\times V_1+\rho_2\times V_2}{V_1+V_2}\\ \\ \\ Calcule:\\ \\ \rho=\frac{1000\times 0,0002+900\times 0,00005}{0,0002+0,00005}=980\frac{kg}{m^3}[/tex]

Answer 2

p=m/V
psuc=1g/cm³
palcool=0,9g/cm³
V1=200ml suc=0,2l=0,2dm³= 200cm³
m1/200cm³=1g/cm³→m1 suc=200g

m2/50cm³=0,9g/cm³→m2alcool=45g

p=(m1+m2)/(V1+V2)= (200g+45g)/(200cm³+50cm³)= 245g/250cm³=49g/50cm³