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?

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Answer 1 · 2017-11-25T01:20:12

Average speed = 5.7 m/s

Average velocity = 2.9 m/s

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 $= "Displacement"/"Time" = "43 m"/"8 s + 7 s" = "2.9 m/s"$

An object travels North at 8 m/s 8 m/s for 8 s8 s and then travels South at 3 m/s 3 m/s for 7 s 7 s. What are the object's average speed and velocity?