Question

(a) The average mpg rating for an older model of a car is 24.8 miles to the gallon and it takes 6.60 x 10^5 J of work done on the car to drive one mile. Given that a gallon of gasoline gives 1.19 x 10^8 J of internal energy to the car, what is the amount of heat released to the atmosphere for each mile you drive the car?

Answer 1

Answer:

the gasoline releases Q=-4138387 J/mile to the atmosphere

Explanation:

from the fist law of thermodynamics

ΔU = Q - W

where ΔU= change in internal energy , Q= heat received , W= work done by the system

then

Q = ΔU + W

knowing that

ΔU = internal energy per gallon * number of gallons consumed in 24.8 miles

= (-1.19 x 10^8 J/ gallon) * 1 gallon /24.8 miles = (-4798387 J/mile)

W = work done by mile= 6.60 x 10^5 J/mile

therefore the heat released per mile

Q = ΔU + W = -4798387 J/mile + 6.60 x 10^5 J/mile = -4138387 J

since Q is negative , energy is released into the atmosphere