Description:

Students will construct a barometer to use in an experiment that they design to measure the air pressure on a daily basis. These observations of air pressure will allow students to determine how weather is affected when a storm is approaching and to predict weather.

The task assesses students' understanding of scientific inquiry including the following skills: observation, background research, scientific procedures (including investigation design, measurement techniques, and error analysis), data collection, data display, scientific questions, formulating a hypothesis.

This task is designed to take students approximately 5 hours over 2 weeks.

Overall Task Content Area:

Physical Science

Specific Knowledge Areas:

Weather and climate patterns and relationship to the water cycle

Performance Expectations:

• conducting investigations
• using equipment
• gathering, organizing, and representing data
• formulating conclusions from investigational data

National Science Education Standards:

8 A SI 1: Abilities necessary to do scientific inquiry: Grades 5-8

1.1 Identify questions that can be answered through scientific investigations. Students should develop the ability to refine and refocus broad and ill-defined questions. An important aspect of this ability consists of students' abilities to clarify questions and inquiries and direct them toward objects and phenomena that can be described, explained, or predicted by scientific investigations. Students should develop the ability to identify their questions with scientific ideas, concepts, and quantitative relationships that guide investigation.

1.2 Design and conduct a scientific investigation. Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables. They should also develop the ability to clarify their ideas that are influencing and guiding the inquiry, and to understand how those ideas compare with current scientific knowledge. Students can learn to formulate questions, design investigations, execute investigations, interpret data, use evidence to generate explanations, propose alternative explanations, and critique explanations and procedures.

1.3 Use appropriate tools and techniques to gather, analyze, and interpret data. The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.

1.7 Communicate scientific procedures and explanations. With practice, students should become competent at communicating experimental methods, following instructions, describing observations, summarizing the results of other groups, and telling other students about investigations and explanations.

1.8 Use mathematics in all aspects of scientific inquiry. Mathematics is essential to asking and answering questions about the natural world. Mathematics can be used to ask questions; to gather, organize, and present data; and to structure convincing explanations.

8 D ESS 1: Structure of the earth system: Grades 5-8

1.9 Clouds, formed by the condensation of water vapor, affect weather and climate.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

National Council of Teachers of Mathematics:

AL1: Understand patterns, relations and functions:
Grades 6-8 f. represent, analyze, and generalize a variety of patterns with tables, graphs, words, and, when possible, symbolic rules

AL4: Analyze change in various contexts:
Grades 6-8 e. use graphs to analyze the nature of changes in quantities in linear relationships

DAP3: Develop and evaluate inferences and predictions that are based on data:
Grades 6-8 e. use conjectures to formulate new questions and plan new studies to answer them

PS2: Solve problems that arise in mathematics and in other contexts:
Grades 6-8

COM2: Communicate their mathematical thinking coherently and clearly to peers, teachers, and others:
Grades 6-8

REP1: Create and use representations to organize, record, and communicate mathematical ideas:
Grades 6-8

General Instructions to the Teacher:

This task is designed to take students Approximately 5 hours over 2 weeks.

Depending on your location, late fall through early spring should provide conditions with fluctuations in pressure suitable for this activity.

• 1 forty-five minute class period to construct barometer.
• 2 weeks daily observations (5-8 minutes)
• 1 or 2 forty-five minute class periods to conduct analyze data and write up results.

Students will be working individually during this exercise.

Students should be ready to work as soon as periods begin. A central supply area, if needed, should be easily accessible. All supplies should be clearly labeled.

Materials for "Barometer Investigation":

Each student will need:

• coffee can
• index card
• rubber cement
• straw
• scissors
• plastic wrap or balloons
• rubber band
• Commercial barometer or internet access to barometric readings

Advance Preparation:

• Teacher introduces this activity with a popcorn demonstration to show what happens when air is heated or cooled. (The popcorn kernels represent the molecules of air.)

Instructions for creating a barometer can be given or students can create their own.

1. Cover the top of a coffee can with plastic wrap. Use a rubber band to hold the plastic wrap in place.
1. Place the straw horizontally on the plastic wrap so that one-half of the straw is on the can.
2. Tape the straw to the middle of the plastic wrap.
3. Tape the index card to the can behind the straw. You may create a scale on the card.
4. Carefully record the location of the straw on the index card.
5. After 15 minutes, record the new location of the straw as often as desired.
6. Continue checking and recording the straw location.
7. Be careful not to place your barometer near a window, as the barometer is sensitive to temperature as well as air pressure.

Facilitate brainstorming of interesting questions that might be answered using their barometer and scientific inquiry.

1. What factors affect air pressure? How can they be tested? (Variables: temperature, moisture, elevation)
1. What happens to the barometer when the air pressure is increased? Decreased? Why?
2. Where is the air pressure the greatest? Inside or outside? Why?
3. How can we predict the weather using the barometer?
4. What happens when a storm comes?
5. How does air pressure cause or affect the weather conditions?
6. In addition to the barometer that they have made, what other tools would be needed? (Like log of local weather conditions, readings from a high-quality barometer)

Safety:

• Be careful.
• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Extensions/modifications:

• Helpful resource: Science Learning Network/Inquiry Resources, 1996, The Miami Museum of Science
• To target the specific NCTM standard(s) to be measured, ask students to compile data on a graph.