Importance of Surface Area

Date: 05/26/2001 at 00:53:09
From: Francine
Subject: The benefits of surface area

Hi Dr. Math!

I was just curious, why is surface area so important? What kinds of 
things depend on surface area? I've heard of towels and how surface 
area is important, but what else? ...in construction? I don't know. 
Please tell me and give me a few examples.

Thanks!

Date: 05/26/2001 at 22:17:26
From: Doctor Peterson
Subject: Re: The benefits of surface area

Hi, Francine.

Let's see ...

In construction, surface area affects planning (how much to buy) and 
costs (how much to charge) in connection with such things as 
wallboard, shingles, and paint.

In manufacturing you will have the same issues - say, the cost of 
making boxes or printing, or sheet metal parts.

In designing, surface area enters into calculations of wind resistance 
and drag in cars or airplanes, pressure and strength of materials.

The surface area exposed to air affects how fast something cools or 
heats or dries out. Elephants, for example, need big ears to increase 
their surface area for cooling purposes, so it's not only human 
designers that have to do these calculations. Many objects have 
complex shapes to increase their surface area: the inside of your 
lungs, intestines, and brain, air cleaners, radiators - and towels, as 
you mentioned. Others avoid flat shapes to minimize surface area 
and avoid drying out: pine needles and cactus for example.

Many things you buy for home use are priced by surface area - or, if 
not, you should figure out their cost per square foot to decide which 
is the best buy: fabric, plastic wrap, and so on.

It looks like surface area is pretty important just about everywhere!

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/   

Date: 05/26/2001 at 23:45:34
From: Francine
Subject: Re: The benefits of surface area

Hi!

Thanks a lot. It really helped me, and you're really smart! Well, I 
just wanted to take this time to thank you for taking your time to 
answer my question.

Take care, and I'll be sure to ask you more questions in the future!

Francine