Lesson 15Using Water Efficiently
Let’s investigate saving water.
- I can answer a question by representing a situation using proportional relationships.
15.1 Comparing Baths and Showers
Some people say that it uses more water to take a bath than a shower. Others disagree.
- What information would you collect in order to answer the question?
- Estimate some reasonable values for the things you suggest.
15.2 Saving Water: Bath or Shower?
- Describe a method for comparing the water usage for a bath and a shower.
- Find out values for the measurements needed to use the method you described. You may ask your teacher or research them yourself.
- Under what conditions does a bath use more water? Under what conditions does a shower use more water?
15.3 Representing Water Usage
- Continue considering the problem from the previous activity. Name two quantities that are in a proportional relationship. Explain how you know they are in a proportional relationship.
- What are two constants of proportionality for the proportional relationship? What do they tell us about the situation?
- On graph paper, create a graph that shows how the two quantities are related. Make sure to label the axes.
- Write two equations that relate the quantities in your graph. Make sure to record what each variable represents.