A cone and a cylinder have the same height and their bases are congruent circles

If the volume of the cylinder is 90 cm^3,
what is the volume of the cone?

A cone and a cylinder have the same height and their bases are congruent circles If the volume of the cylinder is 90 cm3 what is the volume of the cone class=

Respuesta :

Answer:

[tex]30cm^3[/tex]

Step-by-step explanation:

the volume of a cylinder is given by:

[tex]v_{cylinder}=\pi r^2 h[/tex]

and the volume of a cone is given by:

[tex]v_{cone}=\frac{\pi r^2 h}{3}[/tex]

since both have the same height and radius, we can solve each equation for [tex]r^2h[/tex] (because this quantity is the same in both figures) and then match the expressions we find:

from the cylinder's volume formula:

[tex]r^2h=\frac{v_{cylinder}}{\pi}[/tex]

and from the cone's volume formula:

[tex]r^2h=\frac{3 v_{cone}}{\pi}[/tex]

matching the two previous expressions:

[tex]\frac{v_{cylinder}}{\pi} =\frac{3v_{cone}}{\pi}[/tex]

we solve for the volume of a cone [tex]v_{cone}[/tex]:

[tex]v_{cone}=\frac{\pi v_{cylinder}}{3\pi} \\\\v_{cone}=\frac{v_{cylinder}}{3}[/tex]

substituting the value of the cylinder's volume [tex]v_{cylinder}=90cm^3[/tex]

[tex]v_{cone}=\frac{90cm^3}{3} \\\\v_{cone}=30cm^3[/tex]

Answer:

volume of the cone = 30 cm³

Step-by-step explanation:

first write both the formula for  finding the volume a cone and a cylinder

volume of a cone = [tex]\frac{1}{3}[/tex] πr² h

where r is the radius of the cone and h is the height of the cone

volume of a cylinder = πr²h

where r is the radius of the cylinder  and h is the height of a cylinder

since the cone and the cylinder has the same height and they are congruent which implies they have the same radius, then

volume of  a cone =   [tex]\frac{1}{3}[/tex] πr² h

                               = [tex]\frac{1}{3}[/tex] (volume of a cylinder)

                         

   from the question given, volume of the cylinder = 90 cm³

volume of a cone = [tex]\frac{1}{3}[/tex] (volume of a cylinder)

                              =[tex]\frac{1}{3}[/tex] × 90

                               = 30 cm³

Therefore, volume of the cone = 30 cm³