Answer:
The efficiency of the engine is 22.5%.
Explanation:
Efficiency = power output ÷ power input
power output = 55 kW
power input = specific energy×volumetric flow rate×density
specific energy = 44,000 kJ/kg
volumetric flow rate = 27.4 L/h = 27.4 L/h × 1000 cm^3/1 L × 1 h/3600 s = 7.61 cm^3/s
density = 0.73 g/cm^3 = 0.73 g/cm^3 × 1 kg/1000g = 7.3×10^-4 kg/cm^3
power input = 44,000 kJ/kg × 7.61 cm^3/s × 7.3×10^-4 kg/cm^3 = 244.4332 kJ/s = 244.4332 kW
Efficiency = 55 ÷ 244.4332 = 0.225 × 100 = 22.5%
