Entropy Change Due to Driving. Premium gasoline produces 1.23 × 108 J of heal per gallon when it is burned at approximately 400°C (although the amount can vary with the fuel mixture). If a car’s engine is 25% efficient, three-fourths of that heat is expelled into the air, typically at 20°C. If your car gets 35 miles per gallon of gas. by how much does the car’s engine change the entropy of the world when you drive 1.0 mi? Does it decrease or increase it?
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