Average Velocities: Constant Speed on Circular Path

[AdkinsJr]

I have a question about average velocity. It's defined as the net displacement divided by the time. So if I have an object moving at a constant speed on a circular path, is the average velocity zero every time the object returns to the starting point? My reasoning is that the net displacement is zero.

 

[PhanthomJay]

Your reasoning is correct!

 

[Thaakisfox]

Yes that's right. The average velocity is zero. But the average speed is not.

 

[AdkinsJr]

Yes that's right. The average velocity is zero. But the average speed is not.

Ok, that's what I thought. My professor worked out a problem where the object returned to the starting point, and claimed a value for the average velocity. I think she meant average speed and left me confused.

 

[Thaakisfox]

Well yes, that is a common mistake ;)