Which of following are not examples of centripetal acceleration?

1. A car moving around a curve on a road.
2. A rock being swung in a circular path on a string.
3. A rocket moving away from Earth into space.
4. A satellite orbiting around a planet.

The rocket moving away from Earth into space is not an example of centripetal acceleration because centripetal acceleration is directed towards the center of the circular path, whereas the rocket moving away from Earth is not following a circular path.