# Solar Cooker Project

## Title

To investigate the effect of the reflectiveness of the aluminium foil of the solar cooker on the temperature of 100ml of water in the solar cooker after one hour

## Hypothesis

The temperature of 100ml of water in the solar cooker which uses more reflective aluminium foil will be higher than the temperature of 100ml of water in the solar cooker which uses less reflective aluminium foil.

## Independent variable

The reflectiveness of the aluminium foil of the solar cooker

## Dependent variable

The temperature of 100ml of water in the solar cooker after one hour

## Constants

The angle of the flaps

The temperature of the surrounding

The original temperature of the water

## Control

The amount of water

The type of cup used to contain the water

3

## Materials Used

1. Two cardboard boxes that fit inside each other

2. Aluminium foil

3. Black construction paper

4. Cling wrap

5. Sticky tape

6. Scissors

## Steps

1. Cover the base of the smaller cardboard box with black construction paper.

2. Cover the inner sides of the smaller cupboard box and the flaps of the bigger cardboard box with aluminium foil.

3. Cover the smaller cardboard box with a layer of cling wrap.

4. Place the smaller cardboard box into the bigger cardboard box.

1. Solar cooker

2. Styrofoam cup

3. Measuring cup

4. Thermometer

## Steps

1. Pour 100ml of water into the styrofoam cup, measuring it using the measuring cup.
2. Place the styrofoam cup in the solar cooker using more reflective aluminium foil.
3. Use the thermometer to measure the temperature of the water.
4. Measure and record the temperature of the water every 15 minutes until an hour.

5. Repeat steps 1 to 4 two more times.

6. Repeat steps 1 to 5 three times using the solar cooker using less reflective aluminium foil.

Physics Solar Cooker Project

## First Trial (More Reflective Aluminium Foil)

Start: 23 degree Celsius

15 min later: 26 degree Celsius

30 min later: 30 degree Celsius

45 min later: 32 degree Celsius

End (1h later): 35 degree Celsius

## First Trial (Less Reflective Aluminium Foil)

Start: 23 degree Celsius

15 min later: 26 degree Celsius

30 min later: 28 degree Celsius

45 min later: 30 degree Celsius

End (1h later): 33 degree Celsius

## Second Trial (More Reflective Aluminium Foil)

Start: 20 degree Celsius

15 min later: 23.5 degree Celsius

30 min later: 25.5 degree Celsius

45 min later: 27 degree Celsius

End (1h later): 28 degree Celsius

## Second Trial (Less Reflective Aluminium Foil)

Start: 20 degree Celsius

15 min later: 22 degree Celsius

30 min later: 24 degree Celsius

45 min later: 25.5 degree Celsius

End (1h later): 26.5 degree Celsius

## Third Trial (More Reflective Aluminium Foil)

Start: 21 degree Celsius

15 min later: 24 degree Celsius

30 min later: 26 degree Celsius

45 min later: 29 degree Celsius

End (1h later): 31 degree Celsius

## Third Trial (Less Reflective Aluminium Foil)

Start: 21 degree Celsius

15 min later: 23 degree Celsius

30 min later: 25 degree Celsius

45 min later: 26.5 degree Celsius

End (1h later): 28 degree Celsius

## Average (More Reflective Aluminium Foil)

Start: 21.3 degree Celsius

15 min later: 24.5 degree Celsius

30 min later: 27.2 degree Celsius

45 min later: 29.3 degree Celsius

End (1h later): 31.3 degree Celsius

## Average (Less Reflective Aluminium Foil)

Start: 21.3 degree Celsius

15 min later: 23.7 degree Celsius

30 min later: 25.7 degree Celsius

45 min later: 27.3 degree Celsius

End (1h later): 29.2 degree Celsius

## Conclusion

Based on our results, the average temperature of the water in the solar cooker which uses more reflective aluminium foil increased from 21.3 to 31.3 degree Celsius. The average temperature of the water in the solar cooker which uses less reflective aluminium foil increased from 21.3 to 29.2 degree Celsius.

Thus, we can conclude that the average temperature of 100ml of water in the solar cooker which uses more reflective aluminium foil after one hour is higher than the average temperature of 100ml of water in the solar cooker which uses less reflective aluminium foil after one hour.

The experiment results do not reject our hypothesis.

## Scientific Explanations

Since more reflective aluminium foil reflect more light than less reflective aluminium foil, more light will be reflected into the solar cooker using more reflective aluminium foil as compared to the solar cooker using less reflective aluminium foil.

More light energy reflected into the solar cooker means more light energy converted into heat energy to increase the temperature of the water.

Thus, the average temperature of the water in the solar cooker which uses more reflective aluminium foil after one hour is higher than the average temperature of the water in the solar cooker which uses less reflective aluminium foil after one hour.

## Improvement

We think that if we conduct the experiment with the two solar cookers simultaneously side by side, our results will be more accurate and reliable.

## Duty List

Kevin: Brought 2 cardboard boxes, camera and aluminium foil

Nyi Htet: Brought camera and aluminium foil

Nicole: Brought black construction paper, tape and measuring beaker

Li Ting: Brought tape and scissors

## Acknowledgement

Mr Gary Lee: Guided us through this project

Chong Shun Ming: Helped us film the videos

Jessie Ong: Helped us film the videos

Valerie Tan: Helped us film the videos