Mathematical and Physical Journal
for High Schools
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# Problem P. 4657. (September 2014)

P. 4657. A thermally insulated cylinder of cross section 1 dm$\displaystyle {}^2$, containing some air, is attached to the ceiling. Initially the volume of the air is 3 litres, and its temperature is 300 K. The piston which confines the gas into the cylinder is also thermally insulated and has a mass of 10 kg. Another 10-kg object is attached with a rope to the piston and hangs 10 cm above the ground. The air is slowly heated until its volume reaches the value of 4.4 litres.

$\displaystyle a)$ What is the temperature of the gas at the final state?

$\displaystyle b)$ How much heat should be added to the gas?

(5 pont)

Deadline expired on October 10, 2014.

### Statistics:

 73 students sent a solution. 5 points: Asztalos Bogdán, Balogh Menyhért, Bartók Imre, Bereczki Zoltán, Berta Dénes, Blum Balázs, Bugár 123 Dávid, Csathó Botond, Csorba Benjámin, Di Giovanni Márk, Fehér Balázs, Fekete Panna, Forrai Botond, Gróf Tamás, Holczer András, Iván Balázs, Juhász 326 Dániel, Kaposvári Péter, Kasza Bence, Kovács Péter Tamás, Körtefái Dóra, Lőrincz Zoltán, Mándoki László, Marosvári Kristóf, Németh Flóra Boróka, Olosz Balázs, Öreg Botond, Pázmán Előd, Rózsa Tibor, Sáfrán Péter, Sal Kristóf, Südi István, Szabó 789 Barnabás, Szántó Benedek, Szász Norbert Csaba, Tanner Martin, Tihanyi Áron, Tófalusi Ádám, Tomcsányi Gergely, Varju Ákos, Vigh Benjámin, Wiandt Péter. 4 points: Antal Zoltán Ferenc, Kasó Ferenc, Tokai Dániel Marcell. 3 points: 17 students. 2 points: 9 students. 1 point: 1 student. 0 point: 1 student.

Problems in Physics of KöMaL, September 2014