Question

Un vad de forma paralelipipedica are dimensiunile:
L=10cm
l=5cm
h=4cm
a)daca peretii au grosime neglijabila aflati volumul interior in L
b)daca peretii au grosimea de 5 mm aflati volumul interior
C)aflati aria de vopsit in aceasta situatie pe interior si exterior

Answer 1

a)

V = L x l x h = 10 x 5 x 4 = 200 cm³

b)

L₁ = 9 cm

l₁ = 4 cm

h₁ = 3,5 cm

V₁ = 9 x 4 x 3,5 = 126 cm³

c)

Aext = 2Lxh + 2lxh + Lxl =

= 2x10x4 + 2x5x4 + 10x5

= 80 + 40 + 50

= 170 cm²

Aint = 2L₁xh₁ + 2l₁xh₁ + L₁xl1

= 2x9x3,5 + 2x4x3,5 + 9x4

= 63 + 28 + 36

= 127 cm²