Questioning the Logic of Constant Speed Around a Roundabout

[paulhunn]

I am sure i am missing somthing here so if somone could point out the mistake in my reasoning it would be appreciated.
If say you are traveling in a car around a roundabout you must contine to put more power into the engine to remain at a constant speed e.g. 20 mph.
When you reach the maximum amount of power that your car has then you will not be able to retain this constant speed and begin decelarating.
I can't see how this is logical since you would continue to decelarate until you reached very low speeds say 1 mph yet will still be applying the full force the car has to offer to continue in a circular motion and may even reach 0 mph which i know is impossible.

Thanks
Paul

 

[FredGarvin]

With all things being equal (radius of curvature, no skidding, yada yada yada), you will reach an equilibrium between power input and the speed you are at. As long as you are putting out the same amount of power, your speed should remain at some point. You will not constantly decelerate like you are thinking.

 

[charng]

I can understand your confusion regarding the concept of maintaining a constant speed while driving around a roundabout. However, there are a few key factors that you may be overlooking.

Firstly, it is important to note that the power required to maintain a constant speed around a roundabout is not solely dependent on the maximum power of the car. It also depends on factors such as the size and shape of the roundabout, the weight and aerodynamics of the car, and the friction between the tires and the road surface.

Secondly, when driving around a roundabout, the car is not actually moving in a perfect circle. It is constantly changing direction and experiencing centripetal force, which is the force that keeps an object moving in a circular path. This force is provided by the friction between the tires and the road surface, and it increases as the speed of the car increases. This is why you may feel the need to apply more power to maintain a constant speed.

Lastly, while it may seem counterintuitive, it is possible for a car to maintain a constant speed while continuously applying the maximum power available. This is because the power is being used to overcome the forces acting on the car, such as air resistance and friction, and keep it moving in a circular path. The deceleration you mention is only possible if the car is unable to generate enough power to overcome these forces.

In conclusion, the concept of maintaining a constant speed while driving around a roundabout may seem illogical at first glance, but when considering the various factors at play, it is indeed possible and necessary for safe and efficient driving. I hope this helps clarify any confusion you may have had.