Mathematical and Physical Journal
for High Schools
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Problem P. 4242. (March 2010)

P. 4242. A candle is burning in a vertical cylinder standing on the table. The inner wall of the cylinder has a reflexive surface. The height of the cylinder is 30 cm, its diameter is 12 cm, and the centre of the candle light is at a height of 14 cm, 2 cm away from the axis of the cylinder. From which direction will the image of the candle light, which becomes three times wider, be on the top of the cylinder?

(5 pont)

Deadline expired on April 12, 2010.


Sorry, the solution is available only in Hungarian. Google translation

Megoldás. A henger tengelyén és a gyertyalángon átmenő függőleges síkban, a vízszintessel \(\displaystyle 45^{\circ}\)-os szöget bezáró irányban, lefelé nézve (éppen a henger elülső pereme fölött) láthatjuk a láng háromszorosan kiszélesedett képét lobogni.


Statistics:

14 students sent a solution.
5 points:Börcsök Bence, Galzó Ákos Ferenc, Hartstein Máté, Janosov Milán, Jéhn Zoltán, Kószó Simon, Kungl Ákos Ferenc, Lőrincz Dóra, Patartics Bálint, Szabó 928 Attila, Varju 105 Tamás.
4 points:Bolgár Dániel, Neumer Tamás.
3 points:1 student.

Problems in Physics of KöMaL, March 2010