Răspuns:
Explicație:
m = 40.5 g
h = 1 mm
ρ = 2.7 g/cm^3
a) ρ = m/V => V = m/ρ
V = A*h
A*h = m/ρ => A = m/(ρ*h) = 40.5g/(2.7g/cm^3*0.1cm) = 150 cm^2
b) A_patrat = l*l = 5cm * 5cm = 25 cm^2
A1 = A - A_patrat = 150 cm^2 - 25cm^2 = 125 cm^2
ρ = m1/V1
V1 = A1*h
ρ = m1/(A1*h) => m1 = ρ*A1*h = 2.7 g/cm^3*125cm^2*0.1cm = 33.75 g