Respuesta :

Given for the cone:

  • base radius: 3a
  • perpendicular height: 4a

given for the spheres:

  • radius: a

Find volume of cone:

[tex]\sf \hookrightarrow \dfrac{1}{3} \pi r^2h[/tex]

[tex]\sf \hookrightarrow \dfrac{1}{3} \pi (3a)^2(4a)[/tex]

[tex]\sf \hookrightarrow 12\pi a^3[/tex]

Find volume of sphere:

[tex]\sf \hookrightarrow \dfrac{4}{3} \pi r^3[/tex]

[tex]\sf \hookrightarrow \dfrac{4}{3} \pi a^3[/tex]

Divide volume of cone by volume of sphere:

[tex]\sf \hookrightarrow \dfrac{12\pi a^3}{ \dfrac{4}{3} \pi a^3}[/tex]

[tex]\rightarrow 9[/tex]

Therefore proved 9 such spheres can be made using the metal cone.

We know that volume of cone is [tex]12\pi a^3[/tex]

[tex]\sf \rightarrow 12\pi a^3 = 12936[/tex]

[tex]\sf \rightarrow a^3 = \dfrac{12936}{12\pi}[/tex]

[tex]\sf \rightarrow a = \sqrt[3]{\dfrac{12936}{12\pi}}[/tex]

[tex]\sf \rightarrow a =7[/tex]

Therefore the radius of sphere is 7 cm