KöMaL - Középiskolai Matematikai és Fizikai Lapok
Sign In
Sign Up
 Magyar
Information
Contest
Journal
Articles

 

Problem P. 4791. (December 2015)

P. 4791. Recently Peter's boiler makes very strange sounds, as if it would explode at any moment. A repairman was asked to have a look, and he said that limescale has deposited in the tube, and it must be descaled. Peter's small brother asked Peter how the strange sound could arise, and why the thermometer, which measures the temperature of the water, is scaled up to \(\displaystyle 120~{}^\circ\)C, since at that temperature the water would boil. What fraction of the tube is closed by the deposited scale?

What did Peter answer to these questions?

Data: The temperature of the water in the tube is \(\displaystyle 80~{}^\circ\)C, the pressure gauge reads 1.2 bar (excess) pressure, and at normal working conditions the pump makes the water flow at a speed of 3 m/s.

(6 pont)

Deadline expired on January 11, 2016.


Statistics:

25 students sent a solution.
6 points:Asztalos Bogdán, Balogh Menyhért, Blum Balázs, Csorba Benjámin, Forrai Botond, Kasza Bence, Kovács Péter Tamás, Sal Kristóf, Szick Dániel, Tomcsányi Gergely.
5 points:Csenger Géza, Csuha Boglárka, Kardos Réka, Krasznai Anna, Németh Csaba Tibor, Németh Flóra Boróka, Tófalusi Ádám.
4 points:2 students.
3 points:4 students.
2 points:2 students.

Our web pages are supported by:   Ericsson   Cognex   Emberi Erőforrás Támogatáskezelő   Emberi Erőforrások Minisztériuma   Nemzeti Tehetség Program    
MTA Energiatudományi Kutatóközpont   MTA Wigner Fizikai Kutatóközpont     Nemzeti
Kulturális Alap   ELTE   Morgan Stanley