ncept Check
1. Two runners, Andy and Bob, are running a 400-m race (one complete lap around the
track). When the starting gun goes off, Andy begins running while Bob just stands up
and stays at the starting line. Andy runs one complete lap around the track in 50 s while
Bob waits at what is now the finish line. As Andy gets to the finish line, Bob steps over
the line at the same time. What was Andy's displacement? What was Bob's
displacement? What was Andy's average speed? What was Bob's average speed? What
was Andy's average velocity? What was Bob's average velocity?