Question

l=10cm
hh10cm
ro=400kg/m³
m=1kg
L=?​

Answer 1

Răspuns: Lungimea = 25 cm

Explicație:

avem un  obiect cu masa de 1 kg,  cu densitatea de 400 kg / m³ si care are latimea de 10 cm, inaltimea de 10 cm si se cere lungimea .

densitatea = masa / volum

putem afla volumul

V = masa / densitate = 1 kg : 400 kg/ m³ = 0,0025 m³ = 2 500 cm³

Volumul = Lungime x latime x inaltime

Lungimea = Volum : ( latime x inaltime ) = 2500 cm³ : ( 10 cm x 10 cm ) = 2500 cm³ : 100 cm² = 25 cm

Answer 2

 

$\displaystyle\bf\\l=10~cm=1~dm\\h=10~cm=1~dm\\\rho=400~Kg/m^3=0,4~Kg/dm^3\\m=1~Kg\\L=?\\\\Rezolvare:\\\\\rho=\frac{m}{V}\\\\V=\frac{m}{\rho}=\frac{1}{0,4}=2,5~dm^3\\\\V=l\times h\times L=2,5\\\\ 1\times 1\times L=2,5\\\\\boxed{\bf~L=2,5~dm}$