Question

Natalie sets out to run 15 kilometers. Every 30 minutes she checked her pedometer to determine how far she had run. Use the data below to create a proper scientific graph and to answer the corresponding questions.
1. What is the dependent variable?

2. What is the independent variable?

3. How many kilometers had Natalie run after 40 minutes?

4. What was Natalie’s average speed (in kilometers per hour) over the course of her run?
Use the formula Speed = Distance/Times

Answer 1

The answers are:

1. The dependent variable is distance as it varies with the reading time interval of 30 minutes.

2. The independent variable is the elapsed time with a fixed interval of 30 minutes.

3. Natalie had run approximately 8 Km in 40 minutes, marked in the graph. So she must have run, 15-8=7 Km after 40 minutes.

4. To calculate: Average speed, Given: Total distance = 15 Km, Total time elapsed = 150 minutes.

Time in hours will be $\frac{150 minutes}{60 minutes} = \frac{15}{6}$

$Average speed = \frac{Distance}{Time} = \frac{15 \times 6}{15} = 6 Kmh^{-1}$