Velocity Vs. Time Graph Extension Help

[ChEmWen]

1. The problem statement

So I am currently working on an velocity/acceleration lab. My physics teacher requires each lab group to find an extension that goes above and beyond the question that we are supposed to answer with the lab. Each group also needs evidence to prove the extension.

That being said, the above picture is a graph of a "shake'n'go" car (a toy car that when you shake it, it moves) created using a motion detector through. As you can see the car accelerates, then decelerates. The graph looks nice, however at the end of the curve, right when the car comes to a stop, the V v T graph shoots right up to 0 (as circled in the picture).

Our lab groups extension is to figure out what that means, but we can not seem to find any sort of explanation to this.

If anyone could provide information on why this is happening (attached documents or links would work or just a simple explanation), it would be hugely appreciated. THANK you so much!

 

[Simon Bridge]

As for what it means - read the graph and describe, using words, the motion of the car that the graph is telling you. (note - the circles curve can be approximated by three lines...)

What sort of thing causes that sort of motion?
I have a pretty good idea but I can;t actually tell you right out.

 

[ChEmWen]

Well the motion described is that the car is accelerating to the left then decelerating to the left. What our group was assuming was that friction is what caused the jump in the graph. However, when we watched the car, it never appeared as if it stopped abruptly, it appeared as it was accelerating and decelerating at a constant rate.