Creating a solar watch
http://www.fotobabble.com/m/Sk5ObllYdDQvdXc9
speakingpicture ;)
On the 21st of March we were taking part in workshops in Primary School of Palekastro, Crete-Greece, during the 2nd Erasmus + Meeting, short meeting term.
Our task was to build a solar watch on the front wall of the school, towards the South. All the lines were corrected with a felt-tip by students from each country. At the end of the activity pupils wrote their names under the solar watch.
The clock looked very impressive.
How to build a SUNDIAL? (Some procedures)
Step 1 : Choose a sunny wall. The Sundial must be towards south if you’re in Northern Hemisphere, and towards North if you’re in the Southern Hemisphere.
Step 2 : Draw a square 2 cm from the wall margin and set the upper side as segment [AB]. Draw the perpendicular to [AB] passing through E. It intersects [CD] at point F.
Step 3 : Set an horizontal axis (s), with a distance not so far from F but not so close to E. The intersection point will be H.
Step 4 : From the segment [AE] and with the help of a protractor,
mark the angle corresponding to the latitude α, of the place where you want to display the watch.
Step 5 : Draw a segment [HJ], making a 90° angle. The angle EHJ is the latitude of the place (35.5° in Palekastro).
Step 6 : Construct a circle with centre H and of radius equal to the segment [HJ]. Name with the letter K the point of intersection of the circle with the segment [EF].
Step 7 : Having K as centre, construct a semi-circle and mark over it the angles from 15° to 15° starting with segment [EF]. Draw all segments that link the point K to s, passing through the marks already done.
Step 8 : From these new points in s draw all segments until point E and that intersect the line which contains F.
These segments will represent the time lines of the Sundial and should be enhanced with the help of a marker.
So, the right side of the square will be a.m. time. The left side of the square will be p.m. time.
Article made by:
Catarina Gonçalves, Diana Oliveira, Helio Pires, India Boguslawska, Iza Budis, José Gomes, Liwia Misztal, Lucas Esaú, Mila Korolewicz and Zuzanna Jozkow
Geogebra construction :
Kassandra Imanga