The aim of this experiment is to investigate and find the relationship between heat loss (of water) and surface area to volume ratio of animals. To investigate this, we are going to use three flasks of different volume (as the equivalent the animals) and thus different surface areas filled with water.
Surface Area : Volume Ratios
We will be using the following formula for calculating SA:Vol ratios:
SA : Vol
Vol : Vol
100ml flask = 115 : 100 = 1.15 : 1
100 : 100
250ml flask = 230 : 250 = 0.92 : 1
250 : 250
500ml flask = 330 : 500 = 0.66:1
500 : 500
The factors effecting heat loss:
2.Climate / air temperature
3.Mass / Size of the animal
4.Temperature control levels within the animal
5.Surface Area of the animal
6.Circulatory System within the animal, eg double
·3x Clamp Stands
·3x flasks (1x 100ml, 1x 250ml, 1x 500ml)
·Thermometer (To measure the heat loss)
·Stopwatch (To measure time intervals)
·Water Heater (To keep the water hot before the experiment)
1.Water is going to be heated to a certain temperature in the water heater bath.
2.We will then take the correct amount of water out of the bath and it will be placed in the corresponding flask, ie 100ml of water for the 100ml flask.
3.This will be done for all the flasks, 100ml, 250ml and 500ml flasks.
4.The flasks will be placed in a retort stand so that there is no heat loss via conduction from touching the bench.
5.The flasks top will be sealed with a plastic bung, with a thermometer going through it into the center of the water.
6.A reading of the temperature will be taken at two-minute intervals for ten minutes.
7.The readings will be noted on a table of results.
8.The whole experiment will be repeated again to get a better set of average results.
The experiment will occur as follows:
I predict that the rate of heat loss of the water in the 100ml flask will be quicker than that of the 250ml flask and almost twice that of the 500ml flask. This prediction is due to the fact that the 100ml flask has a surface area almost double that of the 500ml flask, for example I predict that if the 100ml flask losses 1 degree C per minute then the 500ml flask will loose half that, ½ degree C per minute.
Animals with large surface area to volume ratios, for example a koala bear found in Australia need this large surface area to volume ratio as so that they can cool of quickly in hot climates. The opposite is true for animals living in cooler climates such as polar bears in the Artic, have small surface area to volume ratio in order to preserve heat - also they have fur to trap warm air particles close to their skin however we are not investigating this factor.
These basic facts are how I came to find my prediction, as well as scientific knowledge found in the 'GCSE Biology' textbook.
In order to create a fair experiment the following factors were kept the same:
1.The whole experiment was done twice in order to get a good set of average results.
2.The flasks were sealed in the correct manner for every flask, in order that no heat escaped through the top.
3.The flasks were held above the bench so no heat was lost to the cold bench, and that no-one was to touch the flask so that no heat was lost via conduction to the skin.
4.The same stopwatch was used throughout all the experiments.
5.The air temperature was kept at the same temperature throughout all the experiments as possible, ie a heater would not be taken into the room etc.
Time (mins)1st exp 100ml (temp. in °C)2nd exp 100ml (temp. in °C)100ml (av. temp in °C)
Time (mins)1st exp 250ml (temp. in °C)2nd exp...