Is velocity constant in uniform circular motion if speed is constant?

[StephenDoty]

I had a test today, there was a question about uniform circular motion. Isn't the velocity constant since the speed is constant? I know angular velocity is constant, but the question's answers only state constant speed or velocity.

Thank you.

Stephen

 

[Phlogistonian]

Velocity is a vector. Speed is a scalar (the magnitude of the velocity). If the direction of motion changes, the velocity changes, even if the speed is constant.

 

[robertm]

Yes the velocity is constant since the speed is constant, but only for tangential speed, you are forgetting the centripetal component of circular motion. As phlogistonian stated velocity is a vector i.e... speed and direction, a change in both or either will cause an acceleration.