PHYSICS
posted by Ami .
Starting from a pillar, you run a distance 200 m east (the + xdirection) at an average speed of 5.0 m/s, and then run a distance 280 m west at an average speed of 4.0 m/s to a post.
Q: Calculate your average velocity from pillar to post.

Total distance = 200280=80
Total time = 200/5 + 280/4 seconds
= 110 seconds
Calculate the average velocity using
average velocity
= total distance / total time
Watch the sign of all quantities. 
0.727

Calculate the horizontal force required to accelerate a 20 kg grocery cart from rest to .50 m/s in 2 s.