Direction of acceleration, vector quantity

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Discussion Overview

The discussion revolves around the concept of acceleration as a vector quantity, particularly in relation to the terms "deceleration" and how they apply when a particle is accelerating in a specific direction. Participants explore the implications of sign changes in acceleration and velocity, as well as the definitions and usage of the term "deceleration" in physics.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether a particle accelerating to the left implies it is decelerating to the right and asks about the sign change from negative to positive.
  • Another participant suggests that swapping the sign of coordinates results in a change of sign for both velocity and acceleration.
  • A different viewpoint states that "deceleration" is not a defined term in physics, emphasizing that when an object slows down, it is still considered to be accelerating.
  • Some participants argue that acceleration that reduces speed is often referred to as deceleration in everyday language, but this may not align with strict scientific terminology.
  • There is a discussion about the usefulness of distinguishing between acceleration and deceleration, with some asserting that magnitude and sign are more important than the terms themselves.
  • One participant highlights that the term "deceleration" can lead to confusion, as it implies a specific type of acceleration that is not universally defined in physics.

Areas of Agreement / Disagreement

Participants express differing views on the definition and utility of the term "deceleration," with no consensus reached on its appropriateness in a physics context. The discussion remains unresolved regarding the implications of acceleration direction and the terminology used.

Contextual Notes

There are limitations in the discussion regarding the definitions of acceleration and deceleration, as well as the implications of sign changes in vector quantities. The varying interpretations of these terms may depend on context and the specific framework within which they are applied.

Kajan thana
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Hi guys,If a particle is accelerating to the left, does this means the particle is decelerating to the right? And also does the sign change from negative to positive?

Many Thanks.
 
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Sure. If you swap the sign of the coordinates, then velocity and acceleration change their sign as well.
 
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My understanding is that deceleration is not a defined term in physics.
Technically, when an object slows down, it accelerates.
 
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Acceleration that lowers the speed of the object is often called deceleration.
 
Kajan thana said:
If a particle is accelerating to the left, does this means the particle is decelerating to the right?
If it's moving to the left, and accelerating to the right, then it is decelerating. "Decelerating to the right" doesn't make sense because deceleration is the rate of reduction of speed which is a positive scalar.
 
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mfb said:
Acceleration that lowers the speed of the object is often called deceleration.
Yes, in everyday conversation but not by Physicists or Mathematicians , in the context of their work. Magnitude and Sign are far more useful than two separate terms. How could you formulate or apply the basic formula for motion under constant acceleration if you had to change the name of what you are dealing with, once the force direction changes?
The Acceleration / Deceleration thing is just one of many pairs of descriptors in common use. Hot / Cold , In / out, Up / down, screw / unscrew etc. To do any useful calculation, the first thing you have to do is to abandon such terms of description.
 
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sophiecentaur said:
The Acceleration / Deceleration thing is just one of many pairs of descriptors in common use. Hot / Cold , In / out, Up / down, screw / unscrew etc.
The "acceleration" above (speed increase) is different from acceleration in physics which encompasses all velocity changes. That's the confusing aspect of bringing up "deceleration".
 
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