If Kinetic friction is a constant can I accelerate forever?

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Discussion Overview

The discussion revolves around the implications of kinetic friction being constant in the context of an object being accelerated by an applied force. Participants explore the relationship between applied force, frictional force, and the resulting acceleration, considering both theoretical and practical aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant states that if a force of 20 N is applied continuously, the object would be accelerating with a 5 N force due to kinetic friction being 5 N.
  • Another participant argues that once the object is in motion, the static friction is irrelevant, and if a force of 6 N is applied, the object would accelerate with a 1 N force.
  • A later reply questions the previous claim, suggesting that the correct acceleration force should be 15 N instead of 10 N.
  • Another participant mentions that more power is needed to overcome friction and that heat produced from friction could become problematic.
  • One participant introduces the concept of work, explaining that work is equal to force times distance, and discusses how increased speed leads to more heat generation due to friction.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between applied force and acceleration, with no consensus reached on the correct interpretation of the forces involved. The discussion remains unresolved regarding the exact dynamics of the situation.

Contextual Notes

There are assumptions about the nature of friction and its effects on acceleration that are not fully explored, such as the transition from static to kinetic friction and the implications of increasing speed on heat generation.

sameeralord
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If a limiting friction of an object is 10N and the kinetic friction is 5 N.

If I apply a force of 20 N continuosly would I be accelerating with a 5 N force forever.
 
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sameeralord said:
If a limiting friction of an object is 10N and the kinetic friction is 5 N.

If I apply a force of 20 N continuosly would I be accelerating with a 5 N force forever.

Hi sameeralord! :smile:

(limiting friction is the maximum value of static friction)

No … you would be accelerating with a 10 N force forever …

once the object has started moving, you can forget the static friction completely (and you can reduce the applied force).

So if you apply a force of 6 N continuously, you will be accelerating with a 1 N force forever. :wink:
 
tiny-tim said:
you would be accelerating with a 10 N force forever
You meant 15 N. Right?
 
DaleSpam said:
You meant 15 N. Right?

Right! :smile:
 
You do need more and more power to overcome friction. The heat produced will become a problem too.
 
Now this is a "work" problem. Are you familiar with "work"?

Work is a measurement of energy, and is equal to force X distance.

In this case, 15N (the force of friction) times the distance the object slides = the heat energy given off (in "joules").

So, when the object is moving faster, it covers more distance per unit time, so it also generates more heat per unit time.
 

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