An object travels North at $9 m/s$ for $7 s$ and then travels South at $7 m/s$ for $6 s$ . What are the object's average speed and velocity?

Question

1554 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-02-12T09:55:51

The average speed is the total distance over the total time.

The total distance i s $63 + 42 = 105$ meters

The total time is $7+6$ seconds $= 13$ seconds

Thus, the average speed is $105/13 ms^-1$ or 8.08 m/s

The average velocity is the total displacement over the total time.

If the object goes $63$ m North and then comes back $42$ meters South, then it is $21$ m North of its starting point.

The total time is the same $= 13$ seconds.

Thus, the average velocity is $21/13ms^-1$ North.

Don't forget to add the direction "North" because velocity is a vector quantity.

An object travels North at 9 m/s9 m/s for 7 s7 s and then travels South at 7 m/s7 m/s for 6 s 6 s. What are the object's average speed and velocity?