A narrow rectangular U-tube has arms and base each l = 300 mm long, cross-section S = 2 c m 2 . The vertical arms hold mercury up to 2 l and one end is sealed. Heating the trapped gas expels all the

Question

A narrow rectangular U-tube has arms and base each $l = 300$ mm long, cross-section $S = 2$ $c m^{2}$ . The vertical arms hold mercury up to $\frac{l}{2}$ and one end is sealed. Heating the trapped gas expels all the mercury. Find the work done by the gas in joules (one decimal; $p_{0} = 1 0^{5}$ Pa, $ρ = 13.6 \times 1 0^{3}$ kg $m^{- 3}$ , $g = 9.8$ m $s^{- 2}$ ).

Answer:

19.20

Solution:

Three stages give $W = S (2.5 p_{0} l + 1.75 ρ g l^{2}) = 2 \times 1 0^{- 4} (75000 + 20992) = 19.2$ J.

TestHub · Accepted Answer

Three stages give W = S ( 2.5 p 0 ​ l + 1.75 ρ g l 2 ) = 2 × 1 0 − 4 ( 75000 + 20992 ) = 19.2 J.

Physics - Heat & Thermo Question with Solution | TestHub

Doubts & Discussion