Concept explainers
(a)
The additional horse power required by a passenger vehicle on the curve.
Answer to Problem 15P
Explanation of Solution
Given information:
Speed
Weight of car
Cross sectional area of car
Radius of the curve
Concept used:
The curve resistance is calculated when the road surface has a horizontal curve. Then the power is calculated using the curve resistance force.
Calculation:
The power of the passenger vehicle is determined by
Conclusion:
Therefore, the additional horsepower developed by a passenger vehicle on the curve is
(b)
The total resistance force developed on the vehicle.
Answer to Problem 15P
Explanation of Solution
Given information:
Speed
Weight of car
Cross sectional area of car
Radius of the curve
Concept used:
The total resistance is the sum of air resistance, rolling resistance and curve resistance of the passenger vehicle.
Calculation:
Take aerodynamic drag coefficient for passenger car as
Rolling resistance force is calculated as
Curve resistance force is calculated as
The total resistance force is calculated as
Conclusion:
The total resistance force on the vehicleis
(c)
The total horse power developed by the vehicle.
Answer to Problem 15P
Explanation of Solution
Given information:
Speed
Weight of car
Cross sectional area of car
Radius of the curve
Concept used:
The total resistance is the sum of air resistance, rolling resistance and curve resistance of the passenger car. Using the total resistance the power of the passenger vehicle is calculated. The power is calculated individually for the straight road surface and for the curve surface. Finally the total power is determined by adding both the powers.
Calculation:
Take aerodynamic drag coefficient for passenger car as
Rolling resistance force is calculated as
Curve resistance force is calculated as
The total horse power is calculated as
Conclusion:
The total horsepower is
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Chapter 3 Solutions
Traffic and Highway Engineering
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