Which of the following statements about centripetal acceleration is true?
i. an object moving with a constant velocity cannot have a centripetal acceleration.
ii. an object moving with a constant speed may have a centripetal acceleration.

An object moving with a constant velocity cannot have a centripetal force

Explanation:

This may looks tricky as it comes down to the definition of velocity. Remember that velocity is a vector, so when we talk about a constant velocity we are not only talking about constant speed only but also constant direction, like a car moving at constant speed on a straight line.  Centripetal accelerations can only be experimented by objects moving on curved paths which means direction is changing and therefore the velocity is changing. That is why An object moving with a constant velocity (intensity and direction) cannot have a centripetal force.