Negative acceleration - change in direction or slowing down?

AI Thread Summary
Negative acceleration can indicate either a change in direction or deceleration, depending on the context of the initial and final velocities. To determine the nature of the acceleration, both initial and final velocities must be analyzed alongside the acceleration value. A negative acceleration implies that the acceleration is acting in the direction opposite to the velocity, but this does not clarify whether the object is slowing down or changing direction. If the velocity is negative, negative acceleration could actually mean the object is speeding up in the reverse direction. Understanding the relationship between acceleration and velocity is crucial for accurate interpretation.
kathyt.25
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Homework Statement


Since we can't tell if a value of negative acceleration means a change in direction or decceleration, how WOULD we be able to tell if its a change in direction or the speed is slowing down (say, if we were given v_initial and v_final)?


Homework Equations





The Attempt at a Solution

 
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If you're given V_i and V_f you know that some negative acceleration had to occur in the direction of motion. You need more than just velocities however, to determine much of anything about the acceleration. Similarly, if you're just given an acceleration, that doesn't necessarily tell you much about how the velocity changes.
 
Y'know, a negative acceleration could even mean something is speeding up, if it has a negative velocity (i.e. if it's moving "backwards")
 
I think it has to do with acceleration being the second derivative of the position vector but I am not entirely sure.
 
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