An internal combustion engine has the following characteristics: (a) the combustion chamber temperature is 1900 ᵒC; (b) the temperature in the exhaust chamber is 430 ᵒC; (c) with the consumption of the equivalent of 7.0 × 10⁹ cal of fuel the engine produces 1.4 × 10¹⁰ J of work in one hour. What is the thermal efficiency of this engine? I.    77% II.    68% III.    56% IV.    48% V.    37% VI.    25%   If necessary, consider: R = 8.314 J/mol∙K 1 cal = 4.19 J kb =1,38 x 10⁻²³ m² kg s⁻² K⁻¹

P₁ P3 Р V. T₁ 2 T₂ 3 T₁ V V. A heat engine consists of a heat source that causes a monatomic gas to expand, pushing against a piston, there by doing work. The gas begins at a pressure of p₁-300 kPa, a volume of V₁=150 cm³, and room temperature, T₁= 20 °C. On reaching a volume of V₂=450 cm³, the piston is locked in place, and the heat source is removed. At this point the gas cools back to room temperature. Finally, the piston is unlocked and used to isothermally compress the gas back to its initial state. The cycle is shown on the pV-diagram in the figure. Molar heat capacity at constant pressure for monatomic ideal gas is Cp = Cv+ R = 5R/2 where the universal gas constant is R = 8.314 J/mol K) Determine the work done on the gas in the process 2-3. Express your answer in J.

4. With 2.56 × 10^6 J of heat transfer into an engine, it performs only 1.50 × 10^5 J of work. (a)What is the engine’s efficiency? (b) How much heat transfer to the environment takes place?

Q2/ Solve the following: 1. Prove that the thermal efficiency of a heat engine is QL = 1- Nen QH 2. Prove that V avg Vf9 x = Q3/ Define the following: Adiabatic Process Нeat Thermal Efficiency Heat Engine Q4/ Write the mathematical equation for the following Enthalpy Ideal-gas equation of state Entropy Specific gravity COPR Pascal's law СОРНР Vacuum pressure