Equipment
- Thermometer
- Bubble wrap
- Elastic band
- Cotton wool
- 4 cans
- goggles
- measuring cylinder
- stopwatch
- gloves
Prediction/ hypothesis (next page)
I think the can with the cotton wool with the lid will be the best insulator for the can because the cotton fibers trap more air than the bubble wrap. This is because air is a good insulator of heat, and cotton wool traps more air than the bubble wrap, and therefore cotton wool with the lid will be the best insulator. The lid will also trap the heat transmitted by convection currents. The lid will trap these convection currents, and therefore the heat will stay in. The ways heat is lost are conduction and convection. Heat is lost through the sides of the an, which is called conduction. Conduction is when particles have lots of thermal energy which turns into kinetic energy (this is also why I now predict that the hotter the water will be, the quicker the heat is lost). This then makes the particles vibrate a lot, which collides with other particles, moving the heat along. This is called conduction. Convection is when the particles have lots of heat to rise, and then they cool down and they sink. This is noticeable in colored liquid being heated. The 1st best insulator of heat will be the cotton wool with the lid, second will be the cotton wool on its own because it has no lid which means heat can be lost through convection waves through the lid, 3rd will be the bubble wrap because it has less air pockets than cotton wool, the cotton fibers contain more air, and finally last will be no insulation because heat is lost through all means. It’s lost through conduction through the sides and through convection through the top. The encyclopedia of Encarta says, ‘cotton wool has many fibers which have pockets of air which makes it a good insulator’. I also predict every 1 minute interval, 2 degrees Celsius of heat would have lost in the water.
Diagram of apparatus
Method
I will be taking the temperature readings from a thermometer. I will repeat my experiment three times so I can get a good average of the set of results and so I can find any patterns
Preliminary work
I tested the starting temperatures. I thought I could start with 90 degrees Celsius (heat will drop quickly), however this was not possible because by the time we put the water in the cans, the temperature would’ve gone down to 70 degrees Celsius, so our new starting temperature was 70 degrees Celsius.
Safety
I will wear safety goggles because of the boiling water. I will also wear an overall, so I do not burn my body with the water. I will wear gloves so I don’t burn my hands with the boiling water.
Instructions for the experiment
- Collect all of the equipment needed for the experiment
- set up the apparatus
- We will start on the no-insulation experiment
- heat the water to 70 degrees Celsius
- pour the water into the can and drop the thermometer in
- remember the safety
- take the readings of 1 minute intervals for 10 minutes
- repeat the experiment 3 times
- write down the results
- Repeat the whole experiment for the bubble wrap, cotton wool, and cotton wool with lid.
- clear up safely
