# An object travels North at # 4 m/s# for #1 s# and then travels South at # 5 m/s# for # 3 s#. What are the object's average speed and velocity?

##### 1 Answer

Average Speed:

Average Velocity:

#### Explanation:

To calculate the object's average speed (direction doesn't matter), we use the formula:

We know that the object traveled for 4 m/s for 1 s then traveled 5 m/s for 3 s, therefore:

Therefore,

To calculate the object's average velocity (direction matters), we use the formula:

Let North be positive and South be negative. We know that the object traveled +4 m/s for 1 s then traveled -5 m/s for 3 seconds, therefore:

Therefore,