Question

1
A runner dashes from the starting line (x = 0) to a point 130 m away and then turns around and runs to a point 11 m away from the starting point in 21 seconds. To the nearest tenth of a m/s what is the average speed?
2
What is the runner's average velocity in the previous problem?

Answer 1

1. average speed
Total distance
= 130 + 130 - 11
= 249 m
Total time = 21 s.
Average speed
= total distance / total time
=?? m/s

2. average velocity
Total displacement
=130-(130-11)
= 11
Total time
= 21 s.
Average velocity = total displacement/total time
= ?? m/s

Answer 2

avg velocity=changedisplacement/time=11m/21s

avg speed=changedistance/time=(130+130-11)/21 m/s