# All Science Fair Projects

## Is the size of a tornado affected by water temperature?

### Materials

• Electrical drill
• 4 Perspex (windshield glass) of about 20cm X 30cm
• 2 wooden boards of about 25cm X 25cm
• 4 wooden blocks of about 5cm X 15cm
• Bathroom exhaust fan
• Measuring tape
• Dry ice
• Extension cord
• Metal plate
• Hot water
• Gloves
• Stopwatch
• Superglue

### Procedure

1. Use the 2 wooden boards as the base and top for the chamber.
2. Cut the Perspex into 4 pieces, each measured to fit the 4 sides of the wooden boards (acting as the walls of the chamber) with gaps.
3. Also, prepare the 2 wooden blocks, which serves the purpose of sliding a Perspex ‘wall’ into place.
4. Overall, it should look something like the diagram below:
5. Make a hole of about 7cm in diameter on the top wooden board to fit the bathroom exhaust fan
6. Glue 2 wooden blocks onto the top and bottom boards each. The width between the 2 blocks should be equal to the thickness of the Perspex.
7. Drill or hammer the various components together
8. Fit the fan into position and connect the electrical wires. Remember to add a power (on/off) switch for the exhaust fan.

Carrying out the experiment:

1. For this experiment, the controlled variable is the water temperatures, which are 10, 20, 30, 40 and 50 degree Celsius respectively. The diameter of the core of the tornado is the dependent variable for this experiment. A few constant variables are the amount of dry ice used, the size of the chamber and the speed of the exhaust fan.
2. Prepare the sample of water one at a time as the temperature needs to be carefully monitored.
3. Heat or chill the water to a temperature of 10 degrees Celsius. Use a microwave or a refrigerator/freezer to help speed up the process.
4. When the optimum temperature is reached, remove the detachable side of the wall by carefully sliding it out of position, and place the plate of water at the center of the chamber.
5. Using the pair of gloves, place 200 grams of dry ice in the middle of the water. Hold it firmly in the middle till it sets in position
6. Reposition the removable wall
7. Turn on the exhaust fan. Start the timer.
8. After a minute, you should be able to observe the early stages of formation of the tornado. Using the measuring tape, roughly measure the diameter of the tornado’s core.
9. After you have completed step 5, repeat all the steps for the different water temperatures of 20, 30, 40 and 50 degree Celsius respectively and