Will a sprinter's speed keep increasing all the time?

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Discussion Overview

The discussion centers on the dynamics of a sprinter's speed, exploring whether a sprinter's speed can continuously increase under constant force application, the effects of air drag, and hypothetical scenarios such as running in space. The scope includes theoretical considerations and the physical limitations of human performance in sprinting.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that a sprinter's speed may keep increasing until air drag and friction counteract the applied force, leading to a constant speed.
  • Another participant notes that air friction scales with the square of speed, implying that maintaining higher speeds requires exponentially more work, though they express uncertainty about the limits of running.
  • A different viewpoint proposes that there is an asymptotic limit to speed, influenced by training, medical advances, and environmental factors such as footwear and running surfaces.
  • One participant elaborates on the relationship between speed, power, and force, indicating that doubling speed could require eight times the power, while also expressing uncertainty about the limits of sprinter performance.

Areas of Agreement / Disagreement

Participants express varying opinions on the limits of a sprinter's speed, with some agreeing on the influence of air drag and others emphasizing physical limitations. No consensus is reached on whether speed can continuously increase or what the ultimate limits might be.

Contextual Notes

Participants acknowledge various factors affecting sprinting performance, including air resistance, physical training, and equipment, but do not resolve the implications of these factors on speed limits.

yasar1967
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when a sprinter starts running he applies force to overcome fraction and air drag. is his speed keeps going up as F=ma governs to? if he's stamina was enough to fuel him for hours will his speed will keep going up and up even though he applies a constant force until the air drag force becomes so big that his muscles' force merely counteracts the fraction plus drag and drops to zero thus reaching constant speed?
What if hypothetically he runs in space on a surface which an artificial fraction made?
I'm aware of the limit due to reaching speed of light and mass increase. I'm not going that far.
 
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Air friction roughly scales with the square of the moving object's speed, so a doubling of the runner's speed quadruples the amount of work he needs to put into maintain this speed. I'm not sure if this is the limit, though, as I don't know much about running. However I am more inclined to believe that actual sprinters are more limited by how fast they can move their legs, since the legs have quite a bit of inertia on their own.
 
I'm of the opinion that there is an asymptotic limit, but the tail could be very long. In addition to more specialized physical training and medical advances, environmental factors will increamentally help (i.e. advances in footgear, running surfaces, and clothing).
 
Nabeshin said:
Air friction roughly scales with the square of the moving object's speed, so a doubling of the runner's speed quadruples the amount of work he needs to put into maintain this speed.
But in addition, work (power, actually), is a linear function of speed even if force is held constant, so actually, the power the runner has to expend is a cube function of speed. Doubling the speed means 8x the power. Four times the force times twice the speed.
I'm not sure if this is the limit, though, as I don't know much about running. However I am more inclined to believe that actual sprinters are more limited by how fast they can move their legs, since the legs have quite a bit of inertia on their own.
Agreed.
 

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