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1-Dimensional Kinematics


Negative Velocity and Positive Acceleration


Observe that the object below moves in the negative direction with a changing velocity. An object which moves in the negative direction has a negative velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a positive acceleration). The "ticker tape" shows that each consecutive dot is not the same distance apart (i.e., a changing velocity). The position-time graph shows that the slope is changing (meaning a changing velocity) and negative (meaning a negative velocity). The velocity-time graph shows a line with a positive (upward) slope (meaning that there is a positive acceleration); the line is located in the negative region of the graph (corresponding to a negative velocity). The acceleration-time graph shows a horizontal line in the positive region of the graph (meaning a positive acceleration).

Anim'n of a Negative Velocity and Positive Accel'n

 


For more information on physical descriptions of motion, visit The Physics Classroom Tutorial. Specific information is available on the following topics:


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Capturé par MemoWeb ŕ partir de http://www.physicsclassroom.com/mmedia/kinema/nvpa.html  le 17/11/01