Question

An object travels North at `4 m/s` for `1 s` and then travels South at `2 m/s` for `4 s`. What are the object's average speed and velocity?

Answer 1

`S_av` of object is `= 2.4 m/s`

`V_av` of object is `=4/5 m/s`

Explanation:

The displacement of the object going `N` for `1s` is:

`N- ((4m)/s)*1s = 4m`

The displacement of the object going `S` for `4s` is:

`S- ((2m)/s)*4s = 8m`

We can take `S` as the positive direction in this case where `N` is opposite, so total displacement is:

`D=8m-4m=4m`

Time taken for the displacement is: `t=5s`

Average velocity is the displacement divided by the total time:

`V_av=(4m)/(5s)=4/5 m/s`

The total distance traveled is #4m+8m=12m

Average speed is the distance traveled divided by the time.

`S_av=(12m)/(5s) = 12/5 m/s = 2.4 m/s`