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Current time:0:00Total duration:1:46

AP.CALC:

CHA‑3 (EU)

, CHA‑3.B (LO)

, CHA‑3.B.1 (EK)

an object is moving along a line the following graph gives the object's velocity over time for each point on the graph is the object moving forward backward or neither so pause this video and see if you can figure that out alright now let's do this together and so we can see these different points on this velocity versus time graph and the important thing to realize is is if the velocity is positive we're moving forward if the velocity is negative we're moving backward and if the velocity is zero we're not moving either forward nor backwards or neither forward nor backwards so right over here we see that our velocity is positive it's a positive two meters per second so that means that we are moving forward now over here our velocity is zero meters per second so this is neither now over here our velocity is negative four meters per second so one way to think about it is we're moving four meters per second backward so I'll write backward now this is interesting this last point because you might be tempted to say all right I'm oscillating I'm going up then I'm going down then I'm going back up maybe I'm moving forward here but remember what we're thinking about here this isn't position versus time this is velocity versus time so if our velocity is negative we're moving backwards and here e our velocity is still negative it's becoming less negative but it's still negative so we are still moving we are still moving backward if we were at this point right over here or at this point then we would be moving forward if our velocity were positive