Mathematical and Physical Journal
for High Schools
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Problem P. 4418. (February 2012)

P. 4418. One end of a thin L-shaped tube is sealed, and the tube is held in the vertical plane. The mercury column of length H/2 confines some air (as shown in Figure 1.), the temperature of the confined air is T1=279 K. The external air pressure p0 is equal to the hydrostatic pressure of a mercury column of height H=76 cm. a) Determine the pressure of the confined air.

Figure 1

b) The tube is turned by 90o, and the air is cooled down such that the air is in the horizontal arm of the L-shaped tube as shown in Figure 2. What is the temperature T2 of the air now?

Figure 2

(4 pont)

Deadline expired on March 12, 2012.

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

Megoldás. \(\displaystyle a)\) \(\displaystyle p_{1}=0{,}76\cdot10^5~{\rm Pa}=57\) Hgcm.

\(\displaystyle b)\) \(\displaystyle T_{2}=\frac{8}{9}T_{1}=248\) K.


133 students sent a solution.
4 points:78 students.
3 points:30 students.
2 points:14 students.
1 point:7 students.
0 point:2 students.
Unfair, not evaluated:2 solutions.

Problems in Physics of KöMaL, February 2012