Within the scientific methods and practices dealing with astronomy, I have developed several sequences on the triangulation, with objective whether a meteor could result in a meteorite, and if so to estimate its drop point. After a review of documents, we reach the conclusion that a meteor that goes to 25 to 35 km altitude is likely to result in a meteorite. It is also necessary to measure or calculate the altitude.
The first session is to present the problem and measurement tools, simplified to give meaning to the concepts of azimuth and elevation of a star, so that to manipulate the object of measurement gives meaning to this same extent.
At first, students have handled a quadrant to measure angles and heights to infer from buildings or trees. The quadrant is
actually consists of a protractor graduated between 0 and 90 °, with a plumb line. It can carry a viewfinder consists of a stud screw and a nail with a head at the same level as the center of the stud.
After two years on paper, here are the students left in the yard. As I could not recover hectometres sports teachers, who were in an outdoor venue, the measurements were not made. I had to improvise, but I find it quite welcome to manipulate other units of length, provided that students handle them with rigor, to the extent with a steady pace as in the calculation and writing.
After students have a measure, I asked students if they were able to measure the height of a building that exceeded the roof of the school.
-no, because we do not know how far it is ground.
So I tried the following, which I found on this site .
is blindfolded with a student.
asked a student to depart the group and make a noise (whistle, clap). The student blinded points to the direction accurately, but very difficult to estimate the distance. Where is the fellow? On a ray, which can be drawn, but it is unclear at what point.
then asked a second student to blindfold. It puts a little further from the first student, then move the transmitter noise and repeating the experiment. Again, students have difficulty in knowing just how far the sound, but are able to fairly accurately pointing direction. By extending the half-lines, we find the position of the transmitter of sound.
Thus, without knowing the distance, with two measures derived different positions, one can determine precisely the source of sound. And place it on a plane. Must still measure the angles of the triangle.
So I took out my theodolite.
It is quite rudimentary but aims to fix ideas. And then the budget math my school does not buy one.
I have a high shelf with a hole for the bear lying around in the attic. I take.
On two opposite sides of a cardboard box, I operate a center hole with a pen. I drew a reporter from the north facing in the negative sense that I glue on the top of the box, after drilling a hole in the center.
on two ice caps, I operate as a hole in the center. I slip a pin into the box, I maintain inside sliding lids and positioning against the two inner sides of the box.
I fixed a bug or a nail just above the reporter, and a quadrant with a thumbtack. The nail and the quadrant are oriented in the same way.
A compass and a level that can position the instrument in the right position to make a measurement of the azimuth and height of a target in one place, then a little further.
After being refitted bathroom, a point is made on the azimuth and height. And then a year in which, from measurements of azimuth, trace the triangle formed by three students.
one can determine the distances with a scale drawing, which recalls the importance of the north. The next few weeks, even using the sine law and the theorem of Al-Kashi, we will determine the distance calculation, then we will determine the position in the sky a meteor, when it flares up and when he goes out, to get an estimate of where it could fall. Patterns in different planes are required to understand the problem.
the plan and the proposed exercises.
Subsequently, the last Senac cover the earth moon distance or distance from a star to the sun.
On these sessions that I find rich and interesting, I still have some questions: I am not very rigorous on the path that is not straight, I use properties first. Certainly, if I do not use them, I'm not far at all. I am under the MPS?
If you have any comments, criticisms, advice, feel free to make comments.
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