A car moves with constant velocity

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SUMMARY

A car moving with constant speed around a circular track maintains a constant speed but does not have a constant velocity due to continuous directional change. The distinction between speed and velocity is critical; speed is a scalar quantity, while velocity is a vector that includes direction. The forum discussion highlights confusion regarding quiz questions on kinematics, specifically questioning the accuracy of answers related to constant velocity. Users expressed the need for a review of the quizzes, as many participants struggled to achieve passing scores.

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tony873004
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Question: Which of the following statements could be true?

a) A car moves with a constant speed around a circular track.

b)A car moves with a constant velocity around a circular track.


This is question #2 from the kinmatics quiz link on this forum.

It marked me wrong for choosing A.

But since speed does not imply direction, I don't see why it's speed can't be constant.

How can the answer be B? If the track is circular, the car is accelerating and therefore changing its direction all the time. One moment it is doing 50mph North. A few moments later it is doing 50 mph South. It's velocity is constantly changing.
 
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The quizes from the forum need to be reviewed and fixed. I think the kinematics one was one where no one got over 60%...
 
tony873004 said:
This is question #2 from the kinmatics quiz link on this forum.

It marked me wrong for choosing A.

But since speed does not imply direction, I don't see why it's speed can't be constant.
You are correct, of course. As Pengwuino says, some of those quizes need to be overhauled.
 
I was in a bit of a fluster over how much I'd forgotten until I convinced myself that the quizzes had to be wrong :wink:

I do think that there were a few questions on some of the tests that I truly did miss though, but that's fine since it serves to reveal areas where my understanding is weak.
 

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