Compute your average velocity in the following two cases: (a) You walk 61.0 m at a speed of 2.26 m/s and then run 61.0 m at a speed of 3.38 m/s along a straight track. (b) You walk for 1.00 min at a speed of 2.26 m/s and then run for 1.85 min at 3.38 m/s along a straight track.