You can SUBSCRIBE and/or leave a comment at the bottom of this KBLOG

The Challenge:

What is an effective way to introduce the concept of surface area to volume ratio?

A Solution:

Surface area to volume ratio concept is a key idea that is important in science and engineering.

As a sphere (cell) or any object gets larger the volume on the Inside increases faster than the surface area of the sphere or outside of any object. Volume is cubed and surface area is squared.

 Using two examples:

Based on physical and Biological constraints you and your students do not have to be concerned about the horrors of Godzilla and the Blob, rest easy tonight, its okay!

1.      Godzilla could never exist based on the SA: V.  Let’s say a creature doubles its size (volume) it will increase its mass (weight) eight times.  It would need unimaginably stronger bones and more muscle and a huge heart and would not be able to get enough energy from food for all that.

2) The Blob (a scary creature of the late 1950s) could never exist as it         gets too big while gobbling up suspecting teenagers the Blob’s insides (volume) cannot be supported by its outside surface (diffusion and waste expulsion).

Resources:

Scary Godzilla Scene

https://www.youtube.com/watch?v=mM8mohcuBQE

Could Godzilla Exist? (See especially 2:19):   

 https://www.youtube.com/watch?v=3cesaPTik_Q 

Trailer – The Blob (1958): 

https://www.youtube.com/watch?v=TdUsyXQ8Wrs