Final answer:
Average speed is the total distance traveled divided by total time, while average velocity is displacement divided by time. James' average speed is 4 km/h, but his average velocity is zero km/h. Displacement plays a critical role in determining average velocity as seen in Jill's and the trucker's example.
Step-by-step explanation:
Calculating Average Speed and Average Velocity
Average speed is defined as the total distance traveled divided by the total time taken. For example, James walks 2 km from his house and back, making the total distance 4 km in 1 hour (30 minutes each way), so his average speed would be 4 km/h. However, his average velocity would be zero km/h because he ends up at his starting point, so there is no overall displacement.
In the case of Jill delivering flyers, her total distance traveled is 3.75 km over 58 minutes. However, her displacement is -0.75 km, the distance due west from her starting point, which is different from her total distance traveled. These examples demonstrate that average speed and average velocity can differ greatly depending on the path taken and the starting and ending points.
For calculating the average velocity of a trucker, if the trucker drives for 0.25 h with a displacement of 16 km south, then the average velocity is 64 km/h to the south since displacement and time are factored in for velocity.