This animation shows an object moving in a circle.
The linear velocity is shown by the blue arrow and the centripetal force
by the red arrow. Notice that although the speed of the object is constant the direction of the linear velocity is constantly changing - this means that the object is accelerating.
The acceleration is the centripetal acceleration and is always directed towards the centre of the circle.

If the speed of the object changes the centripetal force also changes - increasing for an increase in the linear velocity.