A rectangular two-story horse barn is being designed for a farm. The upper floor will be used for storing hay, and the lower floor will have horse stalls that extend 6 feet from both of the longer walls. The barn's length is twice the barn's width, and the lower floor's ceiling height is 8 feet less than the barn's width. What should the dimensions of the lower floor be if the space not used for stalls is to have a volume of 3,840 cubic feet?

Respuesta :

Let the width of the barn be = x feet

So length of the barn = 2x

Height of the barn = x-8

As the stalls are 6 feet longer from both ends hence, we have to find the area with width as x-12 feet

Volume of the space is = 3840 cubic feet

Hence, equation is :

[tex](x-12)(2x)(x-8)=3840[/tex]

Solving this we get

[tex]2x^{3}-40x^{2}+192x=3840[/tex]

[tex]2x^{3}-40x^{2}+192x-3840=0[/tex]

[tex]2(x-20)(x^{2}+96)=0[/tex]

This gives x=20 and x= ±[tex]4\sqrt{6}i[/tex]

Hence, neglecting the square root value we get x = 20 feet

Hence, the width is = x-12 = 20 - 12 = 8 feet

Length is = 2x = 2*20 = 40 feet

Height is = x-8 = 20 - 8 =12 feet

And we can cross check this by multiplying all the three dimensions to get 3840 cubic feet

[tex]8\times40\times12=3840[/tex] cubic feet.


The dimension of the cube is 8, 40, and 12.

Geometry

It deals with the size of geometry, region, and density of the different forms both 2D and 3D.

Given

The lower floor will have horse stalls that extend 6 feet from both of the longer walls.

The barn's length is twice the barn's width,

And the lower floor's ceiling height is 8 feet less than the barn's width.

To find

The dimensions of the lower floor are.

How do get the dimensions of the lower floor to be?

Let x be the width,

The lower floor will have horse stalls that extend 6 feet from both of the longer walls is (x - 12)

The barn's length is twice the barn's width is ( 2x )

And the lower floor's ceiling height is 8 feet less than the barn's width is ( x - 8 )

The volume of 3,840 ft³

We know the formula for the volume.

Volume = langth x width x height

3800 = ( x - 12) ( 2x ) ( x - 8 )

3800 = 2x³ - 40x² + 192x

0 = 2x³ - 40x² + 192x - 3800

It is a cubic equation that can be solved by the hit and trial method.

x = 20, ±4√6 i

The value of x is 20.

Then

length = x - 12 = 20 - 12 = 8

 Width = 2x = 2 (20) = 40

Height = x - 8 = 20 - 8 = 12

So, the dimension of the cube are 8, 40, and 12.

More about the geometry link is given below.

https://brainly.com/question/7558603