Question

read the paragraph about emile. emile began a 200 - kilometer (km) journey through the mountains by going west on a straight path. she traveled a full 25 km in the first hour of her trip. using this paragraph, a student would be able to determine — a. emiles average speed but not her average velocity for the first hour of her journey b. emiles average speed and velocity for the first hour of her journey c. emiles average velocity but not her average speed for the entire journey d. emiles average speed and velocity for the entire journey

Explanation:

Step1: Recall speed and velocity formulas

Average speed = $\frac{\text{total distance}}{\text{total time}}$, average velocity = $\frac{\text{displacement}}{\text{total time}}$.

Step2: Analyze given information for first - hour

In the first hour, distance traveled is 25 km and displacement is also 25 km west (since on a straight path). Time is 1 hour.
Average speed = $\frac{25\ km}{1\ h}=25\ km/h$.
Average velocity = $\frac{25\ km\ west}{1\ h}=25\ km/h$ west.

Step3: Analyze for entire journey

We only know the total distance of 200 km for the entire journey but no information about displacement (if path is not straight) or time taken for the entire journey. So we can't find average speed or velocity for the entire journey.

Answer:

B. Emile's average speed and velocity for the first hour of her journey