Compute all parts of given problem:
Problem: In an experiment, a shearwater (a seabird) was taken from its nest, flown a distance 5080km away, and released. It found its way back to its nest a time 13.8days after release.
Part A: If we place the origin in the nest and extend the +x-axis to the release point, what was the bird's average velocity for the return flight?
Part B: What was the bird's average velocity in m/s for the whole episode, from leaving the nest to returning?
Express your knowledge to solve the above problem.