How Effective Is Cooling Down
?How effective is sweating at cooling you down? DC The temperature of each test tube that contains water which had different conditions that was measured each minute Temperature (±0.05 °C) Minute Dry Dry/Windy Wet Wet/Windy 1 77 82 70 76 2 75 80 64 70 3 72 76 59 65 4 69 73 55 60 5 67 71 53 57 6 65 68 50 53 7 64 66 48 51 8 63 64 46 48 9 61 61 44 46 10 59 60 42 44 11 58 58 41 43 12 56 56 40 41 13 55 55 39 40 14 54 53 38 38 15 53 52 37 37 (All number is put into one whole number) DCP
The percentage change of the temperature of each test tube that contains water which had different conditions that was measured each minute + average percentage change Percentage change in temperature (±0.5 %) Trials Dry Dry/Windy Wet Wet/Windy 1 27 34 31 67 2 31 37 47 51 3 29 60 4 34 32 61 75 5 37 42 52 62 6 31 53 7 35 41 57 63 8 29 39 53 60 9 35 38 61 70 10 37 43 57 54 11 30 36 52 60 Average 32 38 53 62 (All number is put into one whole number) Calculations: Percentage Change in temperature: (Final-Initial)/Final x 100 = % change Initial Data chosen: Dry; Final=53, initial=79.
9-53/79 x 100 = 33% Average percent change in temperature: The sum of all percent changes in temperature for dry / the number of percentages 27 + 31 + 29 + 34 + 37 + 31 + 35 + 29 + 35 + 37 + 30/11 = -32% average percent change in temperature Conclusion The experiment was designed to investigate how sweating is effective on cooling you down. Four test tubes containing water that was all in different conditions of one being a normal test tube covered in newspaper, the same but was blown with a fan, a wet test tube covered in newspaper and the same one that was blown with a fan.
For fifteen minutes, the temperature of the water in the test tube is measured every minute. The results above have shown that the test tube that was covered with dry newspaper’s percentage change is not that great from the original to the final temperature, as it is only 32%. As wind is blown to the same dry newspaper test tube, the percentage change of the temperature increase, being 38%. When it comes to the test tube covered with the wet newspaper the percentage change increase much more with a 53 % change. The highest percentage change, with 62% is the test tube that was covered with wet newspaper and blown by the wind.
In theory, as our body heats up over the normal temperature, our body senses that there is an increase in heat, therefore it releases heat as sweat to cool us down. This is monitored by a part of our brain called the hypothalamus which monitors the temperature of blood in our body. The hypothalamus sends signals when our blood temperature increases or decreases. It sends signals because there is a change in levels, this called negative feedback. The signals sent is then carried by neurons to other parts of the body, this process happens by the arterials being widen, which then will make the blood flow through our skin.
Consequently, our shunt vessels will close; the blood will then transfer heat from our body core to the skin. Thus the temperature of our skin will increase, which then eventually cause our body to sweat. Based on the results that were obtained from the data were similar to the theory, when our body is wet, the temperature changes and decreases more. Similar from the data above, the wet newspaper had a 53% changed compared to 32% dry newspaper. This indicates that when our body is wet, there is a higher chance of a larger percentage change than being dry.
Same, when the wind blows to the newspaper, it made it faster for the temperature to return normal. Furthermore, the Standard Deviation error bars are not too far apart to the column thus it shows that my data is fairly accurate. Evaluation Limitations Why? Suggestion The different initial temperature of water Because the water that was poured into the test tube had different temperatures at the start, the change in temperature of each test tube aren’t constant By boiling the water in a specific temperature, so that when it is poured the temperature will be the same The layering of newspaper for each test tube
When the layering of the newspaper is thick, it will keep the test tube slow down the rate of changing temperature, with a thin newspaper, it will be faster Keep the newspaper layering at the same thickness, make sure each test tube is covered in the same amount of layers Difficult to tell the temperature through the test tube/newspaper Because we can’t raise the thermometer up, there was a difficulty in reading it, as it was covered by the newspaper, so then we had to guess sometimes By layering it with something more translucent, so that it will be easier to see The different distance of the fan
As there was no standards for the length of distance of the fan to the test tube, the percentage change will not be precise By making the distance from the fan to the test tube a control, thus having the same distance for each