Radiation is the emission of heat from the body to its surroundings, mostly to the air. Therefore the penguin will naturally emit a certain amount of heat into the atmosphere and this is wasted.
A penguins skin secrets amounts of sweat on the surface of the skin when it is over heated. As the water evaporates from the moist surface it cools because energy is used for the process of evaporation. And this energy is wasted.
Because of these three factors, this means that the larger the surface area of an animal the faster it will lost heat to the environment.
When the size of an animal increases so does the surface area but their volume increases too. This means that the surface area to volume ration becomes smaller.
To demonstrate this, I will use cubes as an example. By finding the surface area/volume ratio and comparing the two. If this is true then the largest cube should have the smallest surface area/volume ratio
As the volume of an animal increases its cells produce more heat, however the relative amount of space which it loses that heat gets smaller. Therefore a larger animal will lose heat at a slower rate.
For this experiment we will use different sizes of beakers to work out if the above is true. To do this I must calculate the surface area/volume ratio for the beakers we will use in the experiment.
Prediction
I predict that the smallest beaker will lose heat the fastest and the bigger beaker will lose heat much slower. This is because when the size of an object (beaker) increases the surface area/volume ratio decreases. This means that heat will be lost much slower. This should therefore prove why the larger penguins are situated on the coldest place on earth and why the smaller penguins are nearer the warm equator.
Variables
Dependent Variables
We will measure:
- The amount of water in each beaker
- The temperature at the start of the experiment and again at the end of the 30 minutes.
Independent Variables
We will change:
- The volume of the beakers
Controlled Variables
We will keep the same:
- The time that the beakers have to cool
- The type of beakers, all glass
- The shape of the beaker
- The temperature of the room
Strategy for Results
Safety
- Be careful when holding beaker as it will be hot
- Tuck in stools
- Don’t rush around lab.
Obtaining Evidence
Apparatus
- 2 X 2000ml beaker
- 2 X 1000ml beaker
- 2 X 400ml beaker
- 2 X 250ml beaker
- 2 X 100ml beaker
- Stopclock
- 10 X thermometers
Method
- Collect apparatus
- Rinse two beakers of the same size in warm water
- Fill the two beakers to capacity
- Stir the water in each beaker, take the temperatures and record
- Leave the beakers for 30 minutes (leave thermometers in beakers)
- Stir the water again after 30 minutes to make sure water is of equal temperature
- Take temperature and record
- Repeat for accuracy
A Table to Show The Temperature At the Start of and After the 30 Minutes
A Table to Show the Rate of Temperature Loss Compared to the Surface Area to Volume Ratio
Interpreting and Evaluating
Explanation of Results
From the results I have obtained, I can see that the size of beaker greatly affects the rate of temperature loss. The smallest volume of beaker was 100ml and it had the biggest surface area/volume ratio. This therefore caused the rate of temperature loss to be 0.82. Although the beaker was the smallest and it had a smaller surface area to lose heat over, it also contained the smallest volume of water. This means that it doesn’t retain heat as well. So, because the surface area/volume ratio is bigger this shows that the rate of temperature loss is bigger too. As for the biggest beaker, 2000ml, it lost heat at a much slower rate. Its rate of temperature loss was just 0.17. This happened because its surface area/volume ratio was 0.5 and this means that even though it had a bigger surface area compared to the 100ml beaker, the volume of the beaker was bigger too and it was able to retain more heat than it emitted.
Identify Trend In The Graph
From the graph I have drawn it is clear that the surface area/volume ratio affects the rate of temperature loss. The higher the surface area/volume ratio the bigger the rate of temperature loss. This is shown because all the points lie on the curve I have drawn.
Explanation of Conclusions
Due to what I discovered from the experiment I now know why penguins are distributed in the way they are. The smallest penguins are found nearer the warm equator because even though their surface area will be relatively small their volume will also be small too and so their surface area to volume ratio is big. This means that they have a small area to lose the heat over, but as their volume is small they will not be able to make as much heat energy by respiration as they have less cells. This then helps them to maintain a constant body temperature. They live in the warmth because they don’t need to make heat that quickly. In comparison to that, the larger penguins are found in the coldest part of the world because their surface area/volume ratio is small. Although these penguins have a bigger surface to lose heat over, their volume is much more than the smaller penguins, and they therefore have more cells and these cells make a lot more heat energy. This enables them to maintain a constant body temperature through the most extreme cold.
Was your original prediction correct?
From what I have found, it is clear that my original prediction was correct. The smallest beaker lost heat the quickest, and this beaker represents the smaller penguins. The largest beaker lost heat the slowest and this represents the larger penguins.
Reliability of Evidence
As the results I obtained all followed the curve on my graph, I think it is safe to say my findings were very accurate. However to improve accuracy, I could have used several more of each kind of beaker to give a better average temperature loss.
