Can a moving object have a constant speed but a changing velocity?

The magnitude of displacement of a particle moving in a circle of radius $a$ with constant angular speed $\omega$ varies with time $t$ as:

For a particle in uniform circular motion:

$A$ particle $P$ is moving in a circle of radius $a$ with a uniform speed $v$. $C$ is the centre of the circle and $AB$ is a diameter. When passing through $B$,the angular velocity of $P$ about $A$ and $C$ are in the ratio:

$A$ body is moving with a uniform speed of $20 \,m/s$ on a horizontal circle. The change in velocity of the body in half a revolution is

Centripetal acceleration of a cyclist completing $7$ rounds in a minute along a circular track of radius $5 \, m$ with a constant speed,is ......... $m/s^2$.