Question

An object travels North at `12 m/s` for `1 s` and then travels South at `5 m/s` for `7 s`. What are the object's average speed and velocity?

Answer 1

Average speed `5 7/8 m/s`
Average velocity `2 7/8 m/s "South"`

Explanation:

Distance traveled `= 12 m/sxx1 s + 5 m/sxx7s = 47 m`
Total time`= 1 s+7 s= 8 s`
Average speed`= (47m)/(8s) =5 7/8 m/s`

Displacement `= 12 m "North" + 35 m "South" = -12 m "South" +35 m "South" = 23 m "South"`
Average velocity `= (23m)/(8s)= 2 7/8 m/s "South"`