Describe a situation where an object has a change in velocity but constant speed

Speed does not depend on direction, but velocity does.

So, when their is a direction, the velocity would change, but speed would remain constant.

- - the little ball going round and round a spinning roulette wheel

- - a car driving around a curve in the road at a constant speed

- - any Earth satellite in a perfectly circular orbit.

The closest thing to it is a geostationary TV satellite ... they try hard

to make those orbits perfectly circular, and keep correcting them to

stay circular.