Comparing thermal insulation
The materials required for this science project::
- 3 conical flasks
- 3 corks
- 1 electric drill with bits of the right size
- 3 thermometers
- 3 wooden boxes
- 1 bag of sand
- 1 bag of styrofoam balls or fibre
- Tap water
- 1 electric kettle
- 1 clock
1. For this experiment, the independent variable is the type of thermal insulator used – air, sand or styrofoam. The dependent variable is the temperature of the water in the conical flask. This is determined by using the thermometer to measure the temperature. The constants (control variables) are the size of the conical flask, the amount of water in the flask and the size of the wooden box.
2. The electric drill is used to make a hole in the center of the 3 corks. The size of the hole should be just slightly larger than the diameter of the thermometer. The thermometers are then inserted through the hole in the cork.
3. An electric kettle is filled with tap water and brought to the boil. Once the water has started to boil, it is poured into the 3 conical flasks. The corks with the inserted thermometers are used to close the opening on the top of the conical flask. The height of the thermometer is adjusted so that the bottom tip of the thermometer is immersed in the boiled water.
4. The first conical flask is placed inside an empty wooden box. The second conical flask is placed inside another wooden box and it is filled with styrofoam, up to the top of the flask. The 3rd conical flask is placed in the last box and filled with sand until the top of the flask.
5. The time on the clock is noted and the first temperature reading is taken from each of the three thermometers and recorded in the table given below. The temperatures are read from the 3 thermometers every hour for the next 5 hours and recorded in the table given below.