Mathematical and Physical Journal
for High Schools
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# Problem P. 4499. (January 2013)

P. 4499. The mass of an empty balloon is measured with a sensible electronic scale. The mass is 3.7 g. After blowing the balloon the reading on the scale was 4.5 g. The ,,perimeter'' of the balloon, whose shape could well be approximated as a sphere, was measured as 73 cm.

a) How much air was blown into the balloon?

b) What is the excess pressure inside the balloon, if the temperature in the room is 25 oC?

c) What is the drag force exerted on the balloon, when it descends uniformly?

(4 pont)

Deadline expired on February 11, 2013.

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

Megoldásvázlat. $\displaystyle a)$ $\displaystyle m_\text{levegő}=$8,6 g.

$\displaystyle b)$ $\displaystyle \Delta p=1{,}0\cdot10^4~$Pa.

$\displaystyle c)$ $\displaystyle K=0{,}045$ N.

### Statistics:

 141 students sent a solution. 4 points: Antalicz Balázs, Asztalos Bogdán, Balogh Menyhért, Barta Szilveszter Marcell, Berczi Benjámin, Berezvai Orsolya, Bingler Arnold, Blum Balázs, Bognár Tamás, Bugár 123 Dávid, Csáky Pál, Csathó Botond, Csernák Tamás, Csordás Viktória, Czett Antal, Demeter Dániel, Filep Gábor, Forrai Botond, Garai Zoltán, Horváth János, Kárász Milán, Kertész Soma Marcell, Kovács-Deák Máté, Lőrincz Zoltán, Nagy 119 Dóra, Olosz Balázs, Öreg Botond, Pálinkó Petra, Papp Roland, Pázmán Zalán, Pristyák Levente, Sárvári Péter, Sisák Mária Anna, Szabó 8314 Pál, Szilágyi 585 Dezső, Tanner Martin, Trócsányi Péter, Váli Tamás, Varju Ákos, Vasvári Ádám Viktor, Zsiros Ádám. 3 points: 13 students. 2 points: 34 students. 1 point: 31 students. 0 point: 22 students.

Problems in Physics of KöMaL, January 2013