posted by Anonymous .
A person walks first at a constant speed of 4.70 m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 2.50 m/s.
What is the question? Do you want the average speed? The average velocity?
The average speed is the distance traveled (in any direction)divided by the elapsed time. Let D be the distance between the points. 2D is the distance walked.
2D/V(average) = D/2.7 + D/4.5
D cancels out
Vaverage = 3.375 m/s