An object travels North at # 8 m/s# for #8 s# and then travels South at # 3 m/s# for # 7 s#. What are the object's average speed and velocity?

1 Answer
Nov 25, 2017

Answer:

Average speed = 5.7 m/s

Average velocity = 2.9 m/s

Explanation:

Distance along north#= "8 m"/cancel"s" × 8 cancel"s" = "64 m"#

Distance along south#= "3 m"/cancel"s" × 7 cancel"s" = "21 m"#

Total distance#= "64 m + 21 m" = "85 m"#

Displacement#= "64 m North" - "21 m South" = "43 m North"#

Average speed#= "Total distance"/"Time" = "85 m"/"8 s + 7 s" = "5.7 m/s"#

Average velocity#= "Displacement"/"Time" = "43 m"/"8 s + 7 s" = "2.9 m/s"#