Mathematical and Physical Journal
for High Schools
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Problem P. 4600. (January 2014)

P. 4600. A soap bubble is blown with a relatively short drinking straw of diameter d, and then the bubble is left to deflate through the same straw. In one case when the diameter of the bubble was D the time during which the bubble deflated was 8 seconds. Estimate the time during which a bubble deflates

a) if its diameter is also D, and it is deflated through a wider straw of diameter 2d;

b) through a straw of diameter d, if its greatest diameter was 2D?

(5 pont)

Deadline expired on February 10, 2014.


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

Megoldásvázlat. a) Mintegy 2 másodperc alatt.

b) 8\sqrt{2}-ször hosszabb idő, kb. másfél perc alatt.


Statistics:

33 students sent a solution.
5 points:Balogh Menyhért, Bereczki Zoltán, Berta Dénes, Bugár 123 Dávid, Csathó Botond, Dinev Georgi, Fehér Zsombor, Forrai Botond, Holczer András, Horicsányi Attila, Hornyák Szabolcs, Janzer Barnabás, Juhász Péter, Olosz Balázs, Öreg Botond, Sárvári Péter, Szántó Benedek, Varju Ákos.
3 points:3 students.
2 points:2 students.
1 point:7 students.
0 point:3 students.

Problems in Physics of KöMaL, January 2014