What is the Volume of a Solid with a Triangular Base and Square Cross-Sections?

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In summary, the base of the solid is a triangle with vertices at (-8,4), (4,4), and the origin. The cross-sections perpendicular to the y-axis are squares. Using this information, the volume of the solid can be calculated by integrating the cross-section area, which is 9y^2, from 0 to 4. The resulting volume is 192.
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The base of a certain solid is the triangle with vertices at (-8,4) ,(4,4), and the origin. Cross-sections perpendicular to the y-axis are squares.

Then the volume of the solid is __________

i have no clue or don't even know how to start this problem. Well the first thing i did was just graphed the three points they gave me, but that's about it. can someone lend me a hand?
 
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The hight of this solid varies along the y axis. Cosider an element of size dy at a distance y from the origin along the y axis. Find the width of this element using the given information in terms of y. What is the height of the element. (same as the width since cross section is squre). So now you can find the volume of the element.
call this dv
Intergrate dv from y=0 to y= y1 where y1 is the distance from origin to the base of the triangle.
 
  • #3
ProBasket said:
The base of a certain solid is the triangle with vertices at (-8,4) ,(4,4), and the origin. Cross-sections perpendicular to the y-axis are squares.

Then the volume of the solid is __________

i have no clue or don't even know how to start this problem. Well the first thing i did was just graphed the three points they gave me, but that's about it. can someone lend me a hand?
From problem statement:
{Base Vertices (0,0) & (-8,4)} ⇒ {Bounding Base Line} = {y = (-1/2)*x} = {x = (-2)*y}
{Base Vertices (0,0) & (4,4)} ⇒ {Bounding Base Line} = {y = x} = {x = y}
{Base Vertices (-8,4) & (4,4)} ⇒ {Bounding Base Line} = {y = 4}

{Cross-section Area ⊥ y-axis} = {Width}*{Height} =
= {y - (-2)*y}*{y - (-2)*y} = ::: (Square cross-section ⇒ height=width)
= {3y}*{3y} =
= 9*y2

{Differential Volume} = dV = {Cross-section Area}*dy = {9*y2}*dy

[tex] \ \ \ \ (Volume) \ = \ \int_{0}^{4} 9y^{2} dy \ = \ \left [ 3y^{3} \right ]_{0}^{4} [/tex]

[tex] \ \ \ \color{red} (Volume) \ = \ (192) [/tex]


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thanks so much
 

FAQ: What is the Volume of a Solid with a Triangular Base and Square Cross-Sections?

1. What is the "base" of a certain solid?

The base of a certain solid is the flat surface on which the object rests or stands. It is usually the bottom or lowest part of the object.

2. How is the base of a solid determined?

The base of a solid is determined by the shape of the object and the way it is positioned. For example, a cube has a square base, while a cylinder has a circular base.

3. Why is the base of a solid important in geometry?

The base of a solid is important in geometry because it helps determine the shape, volume, and surface area of the object. It also serves as a reference point for measuring and calculating various properties of the solid.

4. Can the base of a solid be changed?

Yes, the base of a solid can be changed by altering the shape or position of the object. For example, a rectangular prism can be rotated to have a different base, or a cone can be cut to have a different shaped base.

5. What is the difference between a base and a face in a solid?

The base of a solid is a specific type of face, as it is always the bottom or lowest face of the object. A solid can have multiple faces, but only one base. The other faces may have different shapes and sizes, while the base is usually a flat surface.

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