Find the volume of material remaining in a hemisphere of radius 2 after a cylindrical hole ofradius 1 is drilled through the center of the hemisphere perpendicular to its base.

Respuesta :

Answer:

Step-by-step explanation:

Inicially we have to separate the sphere into 3 parts:

The donut  +  1 ball cap (or a dome) +  the cylinder hole = the Hemisphere

vide picture

As it shows in the picture we have to find the donut.

The donut  = the Hemisphere - ( 1 dome +  the cylinder hole)

  • The hemisphere = [tex]\frac{4*pi*r^{3} }{6}[/tex] (from the hemisphere formula)
  • 1 dome* = [tex]\frac{1}{6}*pi*(r-\sqrt{(r^{2} -a^{2}})*(3a^{2}+((r-\sqrt{(r^{2} -a^{2}})^{2} )[/tex]
  • cylinder hole = [tex]pi*a^{2}*h = pi*a^{2} *(2r - 2*(r-\sqrt{(r^{2} -a^{2}}))[/tex] (h: cylinder height)

[tex]D = \frac{4*pi*r^{3} }{6} - (\frac{1}{6}*pi*(r-\sqrt{(r^{2} -a^{2}})*(3a^{2}+((r-\sqrt{(r^{2} -a^{2}})^{2} )+ pi*a^{2}*(2r - 2*(r-\sqrt{(r^{2} -a^{2}})) }[/tex]

[tex]D = \frac{4*pi*2^{3} }{6} - (\frac{1}{6}*pi*(2-\sqrt{(2^{2} -1^{2}})*(3*1^{2}+((2-\sqrt{(2^{2} -1^{2}})^{2} )+ pi*1^{2}*(2*2 - 2*(2-\sqrt{(2^{2} -1^{2}})) }[/tex]

By basic algebra we have

D = 5.304

*The dome in the 1st picture is represented by the color orange.Looking into the second picture, the dome formula derivatives from the volume of a dome of a hemisphere. By using the following linear system:

  • triangle_side2 + a2 = r2
  • h + triangle_side = r
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Ver imagen gabrielcardoso