1. The problem statement, all variables and given/known data Starting from a pillar, you run a distance 200m east (the x-direction) at an average speed of 5.0m/s , and then run a distance 280m west at an average speed of 4.0m/s to a post. Calculate your average speed from pillar to post. Calculate your average velocity from pillar to post. I drew a rough sketch on how I would this would look like: http://img365.imageshack.us/img365/449/untitled1zs5.jpg [Broken] I understand that they are on the sime line, as if the runner is running forward and back, I drew it in two seperate lines for convienience. 2. Relevant equations V = X2-X/T2-T1 3. The attempt at a solution At first, I would assume that on they way back, the speed would be 4.0m/s and would remain that for the 80m portion gap between 200 and 280m. Then I decided, that was too easy (and plus I got it wrong), so I think the equation shown above comes into play. But I don't know where to go from there, can anyone stir me into the right direction.