Investigating Atmospheric Pressure with a Cup, Straw and Water
Summary
In this classroom lab activity, students will work with a plastic cup, straw, and drinking water to gain a better understanding of how atmospheric pressure works. This activity should be used with FOSS unit Weather and Water investigation 8 part 1.
Collapse
Learning Goals
1. Students will be able to pull the atmosphere out of the straw allowing the liquid in a glass to come out.
2. Students will be able to see how an imbalance in the atmosphere causes a change in the environment.
2. Students will be able to see how an imbalance in the atmosphere causes a change in the environment.
Context for Use
Grade Level: 8th grade
Class Size: 25 students
Resource Type: Classroom lab activity
Time needed: 15 minutes
Equipment needed: (one for each student) plastic see through cup, straw, water, paper, and pencil
Previous Knowledge: students should have an idea that atmosphere exists all around us. They should also know that atmosphere is pressing on all things on Earth at all times and in all directions.
Class Size: 25 students
Resource Type: Classroom lab activity
Time needed: 15 minutes
Equipment needed: (one for each student) plastic see through cup, straw, water, paper, and pencil
Previous Knowledge: students should have an idea that atmosphere exists all around us. They should also know that atmosphere is pressing on all things on Earth at all times and in all directions.
Description and Teaching Materials
After completing part 1 of investigation 8, have the students gather the following materials: one clear plastic cup and one straw. Have the students fill their cup half full with drinkable water. (This activity can be adapted to work with less available supplies). Once the students have the activity set up, discuss what is happening with atmospheric pressure on the cup, the straw, the water. They should be able to identify that the pressure is stable on all of the equipment. In small groups have the students discuss ways they can make the environment unstable to get the water to move up the straw; they should record their ideas on paper. Once the students have an idea or two written down, they should test their ideas to see what the results will be. Give them about 2 minutes to conduct their activities. Once they are done, have them discuss with their groups the results of the experiments they just completed. On their paper, have them write a results summary explaining what happened and why they think it happened.
One possible solution: place your mouth over the straw and pull the atmosphere out of the straw. Once the atmosphere is removed from the straw, it is unbalanced. The water then rushes into the straw to fill the void left by the atmosphere.
Once students have their results, pull them back together as a large group to discuss what just happened. Go beyond the idea of "I sucked the water through the straw" and get more into the discussion of "by placing your mouth over the straw and pulling out the atmosphere, it left the environment unbalanced. Because Earth strives to keep everything in balance, the water rushes in to fill the void left by the removed atmosphere. That is why water moves up the straw."
One possible solution: place your mouth over the straw and pull the atmosphere out of the straw. Once the atmosphere is removed from the straw, it is unbalanced. The water then rushes into the straw to fill the void left by the atmosphere.
Once students have their results, pull them back together as a large group to discuss what just happened. Go beyond the idea of "I sucked the water through the straw" and get more into the discussion of "by placing your mouth over the straw and pulling out the atmosphere, it left the environment unbalanced. Because Earth strives to keep everything in balance, the water rushes in to fill the void left by the removed atmosphere. That is why water moves up the straw."
Teaching Notes and Tips
This activity should be used with this investigation if there are students who do not fully understand the idea of atmosphere and atmospheric pressure.
Assessment
Collect the papers the students wrote their ideas on for making the environment unstable. Look to see if the students are using the language from class dealing with atmospheric pressure. Look to see how the students planned to cause an unbalanced atmosphere within their cup to get the water to flow.
Review how the students explained what happened in their cup environments and why.
Review how the students explained what happened in their cup environments and why.
Standards
8.I.B.5: Composition and structure of atmosphere