Question

#4
how could the student estimate the average speed in the first 8 hours?
○a use the total distance traveled for the entire trip and determine 8/20 of that total
○b add the distance covered in line segment ab to bc multiplied by 8 hours
○c find the distance covered in line segment ab and bc divided by 8 hours
○d compute the slope of the line segment abc divided by 8 hours

Explanation:

Step1: Recall the formula for average speed

The formula for average speed is \(v_{avg}=\frac{\text{total distance}}{\text{total time}}\).

Step2: Analyze the first 8 - hour interval

In the first 8 hours, the motion is composed of two parts: segment \(AB\) (where the object is moving) and segment \(BC\) (where the object is at rest). The total distance covered in the first 8 hours is the sum of the distances covered in \(AB\) and \(BC\). The distance covered in \(BC\) is \(0\) (since it's a horizontal line in the displacement - time graph, meaning no change in displacement). The total time for the first 8 - hour interval is \(t = 8\) hours.

Answer:

C. find the distance covered in line segment AB and BC divided by 8 hours