Uniform Circular Motion: Why is the velocity changing?

AI Thread Summary
In uniform circular motion, the velocity is constantly changing due to its direction, even though its magnitude remains constant. The acceleration always points toward the center of the circle, indicating a change in direction rather than magnitude. The discussion highlights the importance of understanding velocity as a vector quantity, which is crucial for solving related problems. The question posed in the practice test emphasizes the distinction between direction and magnitude in the context of circular motion. Overall, grasping these concepts is essential for mastering the topic of uniform circular motion.
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I encountered this question in a practice test for an upcoming exam. My first inkling was to answer with (C) because in uniform circular motion, the acceleration always points towards the center of the circle, but the actual answer was D. Do you think this question was just an issue of direction and not magnitude? I know that acceleration nor the velocity are changing in magnitude BUT are changing in direction, given an axis of reference. What do you think? Thanks for your help in advance!
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Hello Baiq and welcome to PF. Use the template (although I agree it's not extremely useful here). Read the guidelines too.
What I think is that you have the right conceptual picture (*). I take it that velocity in this context is a vector quantity and then there is only one answer that is not blatantly wrong.

(*) but then your first inkling would have to be that both B) and C) are right...

And: "given an axis of reference" is not a condition: they change, period.
 
Thank you! Velocity is a vector quantity. That is something I'll remember.
 
And acceleration is too !
 
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