The power required to move car through the air.
The area of the effective flow channel behind the car.
Answer to Problem 124RP
The power required to move car through the air is
The area of the effective flow channel behind the car is
Explanation of Solution
Convert the absolute pressure of the air from mm Hg to kPa.
Write the specific volume of the air.
Here, gas constant is R and temperature while traveling a car at 90 km/h is T.
Write the mass flow ate through the control volume.
Here, the area and velocity at section 1 is
Write the power required to move car through the air.
Calculate the outlet area of the effective flow channel behind the car.
Conclusion:
Substitute
Substitute
Substitute 83.22 kg/s for
Thus, the power required to move car through the air is
Substitute
Thus, the area of the effective flow channel behind the car is
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Chapter 2 Solutions
Thermodynamics: An Engineering Approach
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