Question

An object travels North at `7 m/s` for `4 s` and then travels South at `3 m/s` for `7 s`. What are the object's average speed and velocity?

Answer 1

Average speed = 4.45 m/s
Average velocity = 0.63 m/s

Explanation:

Distance travelled along north = Speed × Time
= 7 m/s × 4s
= 28 m

Distance travelled along south = Speed × Time
= 3m/s × 7s
= 21 m

Average speed = `text (Total distance) / text(Total time)`

= `(28m + 21m) / (4s + 7s)`

= 4.45 m/s

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Displacement = 28 m North - 21 m South
= 7 m north

Average velocity = `text(Displacement) / text(Total time)`

= `(7m) / (4s + 7s)`

= 0.63 m/s