!!!!!!!!!!PLEASE HELP ASAP!!!!!!!!!!
!!!!!!!!!!MY GRADE DEPENDS ON THIS QUESTION!!!!!!!!!!
A silo used to hold grain consits of a cylinder with a height of 25 meters capped by a hemisphere with a diameter of 6 meters. What is the approximate volume of the silo to the nearest cubic meter? Show your work.

Respuesta :

gmany
Look at the picture.

The formula of the volume of a cylinder:

[tex]V_C=\pi r^2H[/tex]

We have:

[tex]d=6m;\ d=2r\to r=3m\\H=25m[/tex]

Substitute:

[tex]V_C=\pi\cdot3^2\cdot25=225\pi\ m^3[/tex]

The formula of the volume of a sphere:

[tex]V_S=\dfrac{4}{3}\pi r^3[/tex]

We have a hemisphere, therefore the formula of the volume is:

[tex]V_H=\dfrac{1}{2}V_S=\dfrac{1}{2}\cdot\dfrac{4}{3}\pi r^3=\dfrac{2}{3}\pi r^3[/tex]

We have:

[tex]r=3m[/tex]

Substitute:

[tex]V_H=\dfrac{2}{3}\pi\cdot3^3=\dfrac{2}{3}\pi\cdot27=2\pi\cdot9=18\pi\ m^3[/tex]

The volume of a silo:

[tex]V=V_C+V_H\to V=225\pi+18\pi=243\pi\ m^3\approx243\cdot3.14\approx763\ m^3[/tex]

Answer: 763 m³.
Ver imagen gmany
Q&A Education