Question

An object travels North at `9 m/s` for `5 s` and then travels South at `7 m/s` for `3 s`. What are the object's average speed and velocity?

Answer 1

Average Speed: `8.25` m/s
Average Velocity: `3` m/s North

Explanation:

`9 m/s N` for `5` s
`rarr` distance traveled: `45 m`; displacement: `45 m N`

`7 m/s S` for `3` s
`rarr` distance traveled: `21 m`; displacement: `21 m S`

Total Distance traveled for `8` s: `45+21 m =66 m`
Average Speed: `66 m` / `8 s=8.25 m"/"s`

Total Displacement after `8` s: `45 mN-21mS=24mN`
Average Velocity: `24 m N"/"8 s=3m"/"s N`