Solar cooker

1. Solar cooker

2. Materials used • Box • Tin Foil • Lens • Cotton • Black paper • Coke can • mirror

3. Design and Construction Skills • First, we found a box, then we covered it with some black papers as black papers can absorb heat from surroundings more efficiently. • Second, we put lots of cotton wool inside the box so as to reduce heat loss to the surroundings. • Third, we added a layer of tin foil to cover up the cotton wool so as to reflect light energy.That makes interior of the box warmer. • Finally,we paint the coke can with black colour so that it can absorb heat energy from the surroundings more efficiently.

4. Application of Physics Principles in the design • We apply several physics principles in this project. Firstly, we collected light energy to warm up the water. Heat is transferred from the sun to the water by radiation. • Next, we covered inside of the box with some cotton wool so as to prevent heat loss to surrounding by conduction. • Afterward, we lined inside with tin foil since light can be reflected by a smooth surface. Therefore, warm air is trapped inside the box.

5. Data Recording

6. The result of the test of cooker Temperature/oC

7. Conclusion • We enjoy doing the project. It is very interesting . We learn more about the greenhouse effect .However, when we tried the second test,we all were very disappointed. It was because there was no bright sun light. We could not test our cooker to have the maximal temperature rise. However, we were glad to finish this project.

8. 4D Lam Wan shue (28) Law Kwok Wai (31) Lui Kwok Lung (33) Tong Lok Ki (35) Wu King Keung (40)

9. The End^^