posted by Vishnu .
Larry leaves home at 2:08 and runs at a constant speed to the lamppost. He reaches the lamppost at 2:15, immediately turns, and runs to the tree. Larry arrives at the tree at 2:29. What is Larry's average velocity during his trip from home to the lamppost, if the lamppost is 308.0 m west of home, and the tree is 688.0 m east of home?
velocity is change of position (a vector) per time.
change of position: final position-initial
avgvelocity = 380W/ total time
= 380 / 21 seconds
= 18.1 m/s
Why is my answer incorrect?