Question

Aria unei bile este 196 pi cm^3, Aflati volumul bilei

Answer 1

 

$\displaystyle\bf\\Explicatii\\\\Bila~este~o~sfera.\\\\Aria~sferei~s~calculeaza~cu~formula:\\\\A=4\pi R^2~[cm^2]\\\\Volumul~sferei~s~calculeaza~cu~formula:\\\\V=\frac{4\pi R^3}{3}~[cm^3] \\\\Calcule:\\\\A=196\pi~cm^2\\\\4\pi R^2=196\pi~~\Big|:\pi\\\\4R^2=196\\\\R^2=\frac{196}{4}\\\\ R^2=49\\\\R=\sqrt{49}\\\\ R=7~cm\\\\Calculam~volumul.\\\\V=\frac{4\pi R^3}{3}\\\\V=\frac{4\pi 7^3}{3}\\\\V=\frac{4\pi 343}{3}\\\\V=\frac{1372\pi}{3}~cm^3\\\\V\approx 475,\!(3)\pi~cm^3$