Can something have negative acceleration and still move faster?

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Discussion Overview

The discussion revolves around the concept of negative acceleration and its relationship with the speed of an object. Participants explore whether an object can experience negative acceleration while still moving faster, considering various dimensions of motion and the implications of vector directions.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that "negative acceleration" indicates that the acceleration vector is opposite to the velocity vector, which typically results in slowing down.
  • Others argue that the interpretation of negative acceleration depends on the direction of the velocity and acceleration vectors.
  • It is noted that if an object has positive velocity and negative acceleration, it is slowing down, while if it has negative velocity and negative acceleration, it is speeding up.
  • A later reply emphasizes that both velocity and acceleration are three-dimensional vectors, suggesting that positive and negative values are relative to defined axes.
  • One participant acknowledges that their earlier statements about acceleration and velocity were applicable only in one dimension, and that multi-dimensional analysis requires breaking down vectors into components.
  • Another participant questions whether the original question implies a one-dimensional context, indicating a potential misunderstanding of the dimensionality involved.

Areas of Agreement / Disagreement

Participants express differing views on the implications of negative acceleration, with some asserting it leads to slowing down while others highlight the importance of vector direction and dimensionality. The discussion remains unresolved regarding the broader implications of negative acceleration in multi-dimensional contexts.

Contextual Notes

Limitations include the assumption of dimensionality in the discussion, as well as the need for defined positive and negative directions in multi-dimensional motion. The rules discussed may not universally apply without considering these factors.

ar53nal14
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Can something be going at negative acceleration be going faster or moving, not stopping or becoming slower?
 
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What does "negative" mean?
 
ar53nal14 said:
Can something be going at negative acceleration be going faster or moving, not stopping or becoming slower?

"Negative acceleration" sounds like the acceleration vector is in the opposite direction of the velocity vector. Net result: slowing down.
 
it depends on the sense of direction
 
If the object has positive velocity, but negative acceleration, it is slowing down.
If the object has negative velocity, but positive acceleration, it is slowing down.
If the object has positive velocity, and positive acceleration, it is speeding up.
If the object has negative velocity, and negative acceleration, it is also speeding up.

Basically, if the acceleration and the velocity vectors are in the same direction, the object is speeding up. If they are in opposite directions, the object is slowing down.

hope that helps.
 
pchalla90 said:
If the object has positive velocity, but negative acceleration, it is slowing down.
If the object has negative velocity, but positive acceleration, it is slowing down.
If the object has positive velocity, and positive acceleration, it is speeding up.
If the object has negative velocity, and negative acceleration, it is also speeding up.

Basically, if the acceleration and the velocity vectors are in the same direction, the object is speeding up. If they are in opposite directions, the object is slowing down.

hope that helps.
Both velocity and acceleration are 3-d vectors, so positive and negative don't have any real meaning for them separately, only relative to each other.
 
I apologize, what i said earlier applied to one dimension only. For 2 or 3 dimensions, you have to break down the acceleration and velocity vectors into x and y or x, y, and z components, respectively.

Then you have to have a defined +x and -x. same goes for y and, if youre in three dimensions, z.

then the rules i stated above apply, but you have to keep in mind that they apply only in that dimension. simply because both the velocity and acceleration vectors for x are positive does not necessarily mean it is speeding up. you need to take into account the other dimension(s).
 
Doesn't the wording of the question -- "...negative acceleration..." -- imply we're discussing 1-dimensional motion?
 
Thats what i assumed, but i guess mathman thought that the OP was in more dimensions...
 

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