Understanding Position-Time Graphs: Can They Determine Speed?

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Position-time graphs can determine both speed and velocity, as speed is the magnitude of velocity. The slope of the graph indicates the direction of motion, with a positive slope representing movement away from the origin and a negative slope indicating movement towards it. To find the instantaneous velocity, one must calculate the slope of the tangent line on the graph, while the absolute value of this slope gives the speed. In one-dimensional motion, the graph effectively conveys both concepts. Thus, position-time graphs are valuable tools for analyzing motion in terms of both speed and velocity.
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Can the position-time graph tell you the speed?
I thought it was ONLY velocity.

Can you please give me an example when IT DOESN'T allow you to find the speed?

Thanks so much in advance!
 
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Speed is the magnitude of the velocity, if you can find the velocity you can always obtain the speed.
 
Presumably we are talking about motion in one dimension, otherwise it's not clear what the position axis represents.

In which case a graph of position vs time gives you speed and velocity. The direction component of velocity comes from the slope of the line. +ve slope is away from the origin, -ve slope is towards the origin.
 
Just to piggyback for additional clarity: if you find the slope of the tangent line on a position vs. time graph you have found the velocity at that instant. The absolute value of the slope is the speed.
 

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