Questioning the Logic of Constant Speed Around a Roundabout

Click For Summary
SUMMARY

The discussion centers on the physics of maintaining constant speed while navigating a roundabout. Paul questions the logic behind needing to apply continuous power to maintain a speed of 20 mph, suggesting that deceleration would occur despite full power input. However, the consensus is that a balance is achieved between power output and speed, allowing for equilibrium as long as the power remains constant. This means that under ideal conditions, a vehicle can maintain a steady speed without continuous acceleration.

PREREQUISITES
  • Understanding of basic physics principles, particularly Newton's laws of motion.
  • Familiarity with concepts of centripetal force and circular motion.
  • Knowledge of vehicle dynamics and power-to-weight ratio.
  • Basic comprehension of speed, acceleration, and deceleration in automotive contexts.
NEXT STEPS
  • Research the principles of centripetal force in circular motion.
  • Explore vehicle dynamics and how power output affects speed in different driving conditions.
  • Study Newton's laws of motion and their application to real-world driving scenarios.
  • Learn about the effects of friction and tire grip on vehicle performance in curves.
USEFUL FOR

Automotive enthusiasts, physics students, and anyone interested in understanding the mechanics of vehicle motion in circular paths.

paulhunn
Messages
33
Reaction score
0
I am sure i am missing somthing here so if someone 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
 
Physics news on Phys.org
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.
 

Similar threads

High School Why is speed constant when centripetal acceleration is constant?
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad Car low average speed vs aero drag relation
  • · Replies 4 ·
Replies
4
Views
2K
High School Filming a passing road sign: speed vs bumpiness
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad The Plane in the Wind Puzzle: Does a Constant Wind Affect the Round Trip Time?
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Is There a Better Model for the Relationship Between Friction and Velocity?
  • · Replies 63 ·
3
Replies
63
Views
5K
High School A scenario of non-uniform circular motion
  • · Replies 4 ·
Replies
4
Views
1K
Graduate 100% energy efficient, constant power rocket
  • · Replies 25 ·
Replies
25
Views
4K
Graduate Riding a roundabout on a train
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad I want a good reference to a discussion of the meaning of "the speed of light is constant"
  • · Replies 60 ·
3
Replies
60
Views
5K
Undergrad Energy to achieve constant acceleration - F=ma and 1/2mv^2
  • · Replies 39 ·
2
Replies
39
Views
15K