Negative or positive of a displacement and velocity

AI Thread Summary
Displacement is defined by its direction, indicating whether it is upward or downward. The sign of velocity (+/-) reflects its direction, with negative velocity indicating movement opposite to the defined positive direction. Similarly, negative acceleration indicates direction rather than speed, meaning an object can still speed up while experiencing negative acceleration. Understanding these concepts is crucial for interpreting motion accurately. The discussion clarifies the relationship between displacement, velocity, and acceleration in terms of directionality.
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I think when we talk about negative or positive of a displacement, we mean that the direction of this displacement which is either going downward or upward. But my question is how about when it says +/-velocity. Does it mean the direction or it means it speeds up or slows down? I think velocity is influenced by displacement according to the formula? so it must be influenced by the sign (+/-) of a displacement. Same happens to acceleration? +/- a. How can i know they mean the direction or speeds.

Thanks a lot.
 
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The sign of a velocity is dependent on it's direction. A negative velocity means that the object is moving opposite to the direction we call positive. A negative acceleration also follows the same argument. Be careful with acceleration. A negative acceleration does not necessarily mean that an object is slowing down. All it means is that the acceleration points in the negative direction.

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yes, it helps. thank you.
 

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