Sergei runs from his house to the post office and back again. For the first 1.0 km, Sergei runs with a speed of 3.0 m/s. For the next 1.5 km, he runs with a speed of 2.5 m/s. He then turns around and runs the final 2.5 km with a speed of 2.8 m/s.
What was Sergei’s average velocity during the run?
What was Sergei’s average speed during the run?
