INTRODUCTION - fill the blank for full credit
bank: 3 boys, divide, surface, compare, girl, volume
 You will build cubes of different dimensions.  The dimension along one side will be doubled with each model. You will then calculate the surface area, volume, and the ratio between the two. A ratio is used to _______________
2 quantities. To find the ratio you ________ one quantity by the other. If a ratio girls/boys is 3:1, it means there
are ________________ for every ____________. Find the ratio girls/students in this class ______________
Find the ratio boys/students in this class ___________. Find the ration instructor/students in this class _________.
If you compute the ratio surface/volume of a cube, you will find out how much ___________ (cm²)  is available  for every unit of _________ (cm³).

PROCEDURE
Remember: Volume ( cm³)  = V = L (cm) x W (cm) x H (cm)    (for a cube or any box)
total surface  area (cm²)=  A = sum of the areas of the faces = L (cm) x W(cm)  x 6

step1: Measure one size of one cube. 1 side = _____ cm. So volume of 1 cube = ______ cm³ (see above).
Surface = _____ cm² (see above). The ratio surface / volume = A / V = _________.
(just divide, you don't need to worry about units here) )
Look at the TABLE BELOW. I reported step1  data  in the table.

step2: Now build a cube with a side = 2cm. Find its total area A , its volume V and the ratio A/V.
Fill the table below. (see step 1).

step3: do the same thing again for a cube with side = 3cm and then with a cube with side = 4cm. Fill the table.

DATA TABLE: Cell size comparison
cell:	dimension (cm)	Surface area A (cm2)	volume V (cm3)	ratio : Surface area to volume
1	1 x 1 x 1	(1 x 1) x 6 = 6	1 x 1 x 1 = 1	6/1 = 6
2	2 x 2 x 2	_______________	__________	_____________
3	___________	_______________	____________	____________
4	_________	_______________	____________	___________

ANALYSIS. 

1)
Which model has the largest surface area? ______

Which model has the largest volume? ______

Which model has the largest ratio? ______

So,  as you increase the volume of the cube or any object, the ratio surface/volume ___________. This means there is less surface available per each unit of volume.  

2)
A mouse needs to eat all the time to stay alive, whereas large animal like elephant need to eat only once in a while to keep their metabolism going . Can you understand why after doing this lab ? (a model for a mouse would a a small cube and a model for an elephant would be a big cubet).
hint: more surface, means more exchange with the outside (inside is the body). exchange can be the loss of heat.


3) Is it better to peel off 1 pound of small potatoes or 1 pound of large potatoes ? why ?

4) Every living thing processes food for energy. This energy creates heat that radiates from its surface.
A) why do large object cool more slowly than similar small object ?
hint: big weight means small surface / weight  versus small weight

B) why is a beached whale more likely than a beached dolphin to experience overheating ?
hint: less surface means less exchange with the outside so less heat loss

C) Why are larger mammals found closer to the poles than the equator ?
hint: less surface means less heat loss

D) If a woman and a small child fall in a cold lake, why is the child in greater danger of hypothermia ?

E) why elephant have large ears?
hint: large ears means increase of surface.