A sample of an ideal gas is in a cylinder fitted with a piston. As 5.76 kJ of heat is supplied to the gas to raise its temperature, the pressure of the gas is adjusted so that the state of the gas cha

Question

A sample of an ideal gas is in a cylinder fitted with a piston. As 5.76 kJ of heat is supplied to the gas to raise its temperature, the pressure of the gas is adjusted so that the state of the gas changes from point A to point B along the semicircle in the P-V graph shown in figure. Find the change in internal energy of the gas (in kJ). Take $π = 22/7$ .

Answer:

3.20

Solution:

$W =$ area under the semicircle $= \frac{π}{2} [200 \times 2.8] + (300 \times 5.6) = 2560$ J $= 2.56$ kJ.

By the first law: $Δ U = Q - W = (5.76 - 2.56)$ kJ $= 3.20$ kJ.

TestHub · Accepted Answer

W = area under the semicircle = 2 π ​ [ 200 × 2.8 ] + ( 300 × 5.6 ) = 2560 J = 2.56 kJ. By the first law: Δ U = Q − W = ( 5.76 − 2.56 ) kJ = 3.20 kJ.

Physics - Heat & Thermo Question with Solution | TestHub

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