Lesson 9 of 15
Objective: SWBAT identify the effects of rising altitude on air pressure.
Teacher Tip: This lesson is designed for students to make the connection between air pressure and altitude. They will do this by relating pressure to a squeezing effect. They will graph data into a line graph in order to see the correlation between the two, thus addressing SP4 and 5. You will need graph paper for this lesson.
To begin the lesson, students start by thinking of the story of the Princess and the Pea. They are to wonder about what it would feel like to be the pea underneath all of those mattresses. They record their responses in their student notes sheet:
ENGAGE: Think about the story of the princess and the pea. What would it feel like to be the pea?
Note: Some students have not heard this story and you may have to begin class by recalling the story.
After students have had a few minutes to think about being "squeezed" underneath all of those mattresses, I ask them to think about what would happen if we were to add a few more to the stack or take a few away or move the pea to a different position within the stack. They are guided through these questions in the EXPLORE section of their notes sheet, in which they will record their responses:
EXPLORE: If some of the mattresses were to be removed from the pea, what would it feel like? What if we added more mattresses to the pea?
Next, students watch a video that demonstrates what happens when air pressure increases. They see how when pressure increases, objects react (sometimes by being squeezed apart). They answer the questions on their notes sheet while watching:
EXPLAIN: Watch the Atmospheric Pressure video and write definitions for the following words.
Based on the demo, what happens when there is more pressure?
Air pressure is...
Before watching, I preview the question by reading aloud to the students and asking them to tell me what they are looking for when watching. When finished, I ask them to share a few responses and then, as a class, we define air pressure and altitude.
Students graph the following data points in a line graph in order to see the relationship between air pressure and altitude.
ELABORATE: Graphing air pressure and altitude.
Graph the following points on the graph paper for your table.
I usually do this as a whole class activity for the initial set up of the graph (creating x and y axis, intervals on the axes, and plotting the first few points) and then set the students "free" to complete the remaining points. See student graph sample and student graph sample 2 and student graph sample 3 for examples of student graphs.
The final task is for students to analyze their line graphs and make the connection between air pressure and altitude. They will record their responses individually in their notes sheets:
EVALUATE: Explain what happens to air pressure as altitude increases.