To measure heat loss in two test tubes which represent bodies, one which sweats (the wet test tube) and one body which doesn’t sweat (the dry test tube).
Apparatus:2 Thermometers2 Stoppers2 Boiling Tubes2 Measuring CylindersCotton WoolPaper TowelsTimerWaterPrevious Knowledge:I know that when the body gets to hot, the sweat glands produce sweat, which evaporates of the skins surface, and cools the body as it evaporates. The evaporation of water needs a lot of heat energy. This heat energy is taken from the body when the sweat evaporates.
Prediction:I think that the wet test tube will cool the fastest because this is what happened during my preliminary experiment. The wet test tube cooled the water down by 22OC more than the dry test tube. Also my knowledge of the way the human body works helps support my prediction because the body produces sweat to cool the body down, and the wet test tube acts in the same way.Diagram:Fair Testing:For all the experiments I’m going to conduct I will have to make sure I do them fairly. I will use exactly the same apparatus, the same amount of water in each test tube as well as the same amount of paper towelling each time.
I will measure the temperature change in each test tube for the same amount of time and will begin measuring the temperature when the temperature in each test tube is the same.Plan: Preliminary Experiment.1. I started by setting up my apparatus as it’s shown in the diagram above.
2. I then boiled some water in a kettle.3. After the water had boiled I measured out 25cm3 of water in two measuring cylinders and then pouring into each boiling tube.4. I then began taking readings for 20 minutes, every minute and recorded them.5.
My preliminary experiment wasn’t as successful as possible because the starting temperatures of each boiling tube were not the same. This was because the wet paper towelling around one of the boiling tubes had already cooled the boiling tube so when I pored the water in it cooled very rapidly.Results:Time (mins)Temp. in dry Test tube (OC)Temp. in wet test tube (0C)07265171632705736952467505664766544764428634096239106137116036125935135834145733155632165531175531185430195430205230Calculations:The dry boiling tube cooled by 20OC, and the wet boiling tube cooled by 35OC.The wet boiling tube cooled 22OC more than the dry boiling tube.Plan: Experiment 2.1.
I decided to test each boiling tube separately.2. I did this by pouring 25cm3 of boiling water in to a boiling tube covered in a wet paper towel and the taking the readings for 10 minutes because the most significant change in temperature occurs between 0 and 10 minutes in my preliminary experiment.3. I then poured some more boiling water into a boiling tube covered by a dry paper towel. I waited for the temperature to drop so the starting temperature was the same as the starting temperature for the wet test tube.4. I then took readings of this boiling tube for 10 minutes.
Results:TimeTemp. in dry Test tube (OC)Temp. in wet test tube (OC)06767166612655636353461495604665944758428574095639105537Calculations:The dry boiling tube cooled by 12OC, and the wet boiling tube cooled by 30OC.The wet boiling tube cooled 18OC more than the dry boiling tube.Plan: Experiment 3.
1. I decided use a stopper at the top of the boiling tube to plug it up.2.
I did this by pouring 25cm3 of boiling water in to a boiling tube covered in a wet paper towel and then poured 25cm3 of boiling water into a boiling tube covered by a dry paper towel. At this point, the temperatures were not the same, so I blew on the top of the water in the boiling tube covered in the dry paper towel to bring the temperature down.3. I then took readings of this boiling tube for 10 minutes.Results.
TimeTemp. in dry Test tube (OC)Temp. in wet test tube (OC)07171169632675936556463545625366050759498544795546105445Calculations:The dry boiling tube cooled by 17OC, and the wet boiling tube cooled by 26OC.The wet boiling tube cooled 9OC more than the dry boiling tube.
Plan Experiment 4.1. The plan for experiment was exactly the same as experiment 3 except I used cotton wool to plug up the boiling tube instead of using a stopper.Results:TimeTemp. in dry Test tube (OC)Temp. in wet test tube (OC)07070169682676436660465565645566353761508604996047105945Calculations:The dry boiling tube cooled by 11OC, and the wet boiling tube cooled by 25OC.The wet boiling tube cooled 14OC more than the dry boiling tube.Plan Experiment 5.
1. For this experiment I decided to cover the boiling tubes in dry paper towels and then pour 25cm3 of boiling water in to each boiling tube.2. I then made sure that the temperature of the water was the same for both boiling tubes and took my first reading for 0 mins.3. I then wet one of the boiling tubes, and took my second reading a minutes later.Results:TimeTemp.
in dry Test tube (OC)Temp. in wet test tube (OC)06363162552605036048458465574565642755418554095438105337Calculations:The dry boiling tube cooled by 10OC, and the wet boiling tube cooled by 26OC.The wet boiling tube cooled 16OC more than the dry boiling tube.Plan Experiment 6.1.
I did this experiment in exactly the same way I did experiment 5 because I thought that this was the most accurate method, so I wanted to make sure my results were accurate.Results:TimeTemp. in dry Test tube (OC)Temp. in wet test tube (OC)06464162572615436051459495584765745756438554195440105339Calculations:The dry boiling tube cooled by 11OC, and the wet boiling tube cooled by 25OC.The wet boiling tube cooled 14OC more than the dry boiling tube.