From Pillar to Post. Starting from a pillar, you run 200 m east (the + x-direction) at an average speed of 5.0 m/s and then run 280 m west at an average speed of 4.0 m/s to a post. Calculate (a) your average speed from pillar to post and (b) your average velocity from pillar to post.

Solution 4E The time taken to move 200 m is time=distance/speed =200/5 =40 s The time taken to move 280 m is time=distance/speed =280/4 =70 s Average speed from pillar to post is given by avg.speed=total distance/total time =480/110 =4.36 m/s The displacement from...