Inclination angle of a banked turn in a road for a maximum speed

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SUMMARY

The discussion focuses on calculating the inclination angle (theta) of a banked turn for vehicles, emphasizing the relationship between velocity (v), radius (r), gravitational acceleration (g), and the coefficient of friction (μ). The equation tan(theta) = (v^2)/(r*g) is central to the calculations, with the need to incorporate μ to reflect real-world scenarios. Participants highlight the importance of ensuring that the angle allows for safe navigation at both high speeds and low speeds without slipping, thus establishing constraints based on the coefficient of friction.

PREREQUISITES
  • Understanding of basic physics concepts, specifically circular motion.
  • Familiarity with the coefficient of friction (μ) and its implications on vehicle dynamics.
  • Knowledge of the equation tan(theta) = (v^2)/(r*g) for banked turns.
  • Concept of forces acting on a vehicle during a turn, including friction and normal forces.
NEXT STEPS
  • Study the effects of varying the coefficient of friction (μ) on banked turns.
  • Explore real-world applications of banked turns in highway design and racing circuits.
  • Learn about the dynamics of vehicle stability at different speeds on banked curves.
  • Investigate the relationship between radius of curvature and maximum safe speed on banked roads.
USEFUL FOR

Engineers, physics students, and automotive designers interested in vehicle dynamics, road safety, and the design of banked curves for various driving conditions.

Andrei0408
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Homework Statement
In a real case, for a real radius curve and a real sliding
friction coefficient, find the inclination angle of a road for a maximum speed.(Ex. two-lane road, highway, racing circuit, railroad; tire-asphalt, meta-metal friction)
Relevant Equations
tan(theta)=(v^2)/r*g; μ=tg(alpha)
I know the solution is based on velocity and the sliding friction coefficient, and I believe I should put the condition Fcf smaller than Ff, but I just don't understand how to include μ in the solution, to find the angle. Even if you don't solve the problem, I just need to understand the concepts, please!
 
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Welcome, andrei0408! :cool:

What is that you don't understand specifically?
The vehicle naturally tends to keep going straight while the tires force it to follow a circular trajectory.
Friction force between the tires and the road is needed to achieve that change of direction.
The available friction force is certain percentage of the weight of the vehicle.
For different surfaces of the road, that percentage is called coefficient of friction (μ).
 
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Lnewqban said:
Welcome, andrei0408! :cool:

What is that you don't understand specifically?
The vehicle naturally tends to keep going straight while the tires force it to follow a circular trajectory.
Friction force between the tires and the road is needed to achieve that change of direction.
The available friction force is certain percentage of the weight of the vehicle.
For different surfaces of the road, that percentage is called coefficient of friction (μ).
Well I need to find theta from the equation tan(theta)=(v^2)/r*g, but I also know that I need to include μ in order to solve for a real case.
 
Andrei0408 said:
Homework Statement:: In a real case, for a real radius curve and a real sliding
friction coefficient, find the inclination angle of a road for a maximum speed.
I must be missing something (is there another constraint?). As you go faster and faster the bank angle must rise to make your normal force support the car. Are there any other constraints? If not, then very fast speed is achieved with a maximum bank angle, it would seem.

Kind of like these guys:

 
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Andrei0408 said:
Homework Statement:: In a real case, for a real radius curve and a real sliding
friction coefficient, find the inclination angle of a road for a maximum speed.(Ex. two-lane road, highway, racing circuit, railroad; tire-asphalt, meta-metal friction)
Relevant Equations:: tan(theta)=(v^2)/r*g; μ=tg(alpha)

I know the solution is based on velocity and the sliding friction coefficient, and I believe I should put the condition Fcf smaller than Ff, but I just don't understand how to include μ in the solution, to find the angle. Even if you don't solve the problem, I just need to understand the concepts, please!
Since it specifies realistic situations, you should assume it is also a requirement to be able to go arbitrarily slowly on the same road without slipping down. That gives a max angle in terms of the coefficient.
 
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haruspex said:
Since it specifies realistic situations, you should assume it is also a requirement to be able to go arbitrarily slowly on the same road without slipping down. That gives a max angle in terms of the coefficient.
Oh, interesting. That would definitely add a constraint. :smile:
 

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