etwinning project

1. OUR SOLAR ENERGY DEVICE: Solar collector etwinningproject

2. When a three dimensional parabola is aimed at the sun, all the light that falls upon its mirrored surface is reflected to a point known as the focus. If a black cooking pot is placed at the focus it will absorb the light's energy and become very hot. A satellite dish is an example of a parabolic that can be made into a cooker.

3. Diagram shows the unique reflecting properties of the parabola .

4. The Mathematics Using the rectangular coordinate system allows us to draw a picture and determine mathematically where the focus is located . The focus can also be found by direct observation after we have lined the dish with a reflective material. Hold a piece of cardboard close to the center of the dish, then move it up and down toward the sun and back. A circle of light will appear on the underside of the cardboard. When the circle is smallest, the position of the focus is found.

5. We used a satellite dish from trush

6. a satellite dish…. the shape of a satellite dish could be called an elliptic paraboloid. By observing the shape through the perspective of each coordinate plane, one can see the two-dimensional curves that the elliptic paraboloid consists of. Parallel to the xy-plane is and ellipse, parallel to the xz-plane is a parabola, and parallel to the yz-plane is another parabola. The standard variable equations to these functions are: Parabola: y = ax2 + bx +c Ellipse: x2+ y2 = 1 However, the structure of a satellite dish does not consist of an ellipse but a circle. In the equation of an ellipse, the square roots of a and b constitute the length of the lines parallel to their corresponding x- and y-axes, starting from its center. In order to form a circular paraboloid, a and b would have to be equal.

7. Unfixing the bracket

8. Some calculations

9. We used the most popular material used to line the dish : A reflective, mirror, self-sticking aluminum paper.

10. Cutting to pieces…

15. Finally the dish is ready

16. And it BURNS!!!

17. We can cook now …

18. You can watch the video in : http://www.youtube.com/watch?v=hcpYMhgvtsA