# Water fountain scale factor , volume surface area

• May 4th 2011, 06:10 AM
vaironxxrd
Water fountain scale factor , volume surface area
You decide that 0.25 inch in your model of a cylinder shape water fountain corresponds to 12 inches of the actual tower.

The top of the tower has a diameter of 20 feet .
The height of the actual tower is 32ft.

Find the volume of the actual tower . ( I got pi*3200ft(cube) )

Now use the result above to find the volume o the scale model I get confused here
• May 4th 2011, 07:41 AM
earboth
Quote:

Originally Posted by vaironxxrd
You decide that 0.25 inch in your model of a cylinder shape water fountain corresponds to 12 inches of the actual tower.

The top of the tower has a diameter of 20 feet .
The height of the actual tower is 32ft.

Find the volume of the actual tower . ( I got pi*3200ft(cube) )

Now use the result above to find the volume o the scale model I get confused here

A scale is nothing but a proportion:

$\displaystyle \dfrac{model}{real} = \dfrac{0.25}{12} = \dfrac1{48}$

Now multiply this equation by "real" and you'll get:

$\displaystyle model = \dfrac1{48} \cdot real$

Plug in the real values to get the model measures:

$\displaystyle diameter\ of\ model = \dfrac1{48} \cdot 20' = \dfrac5{12}' = 5''$

and so on ...