Warm and Cold Air

Grade Level:

• 3rd, 4th, and 5th

Objectives:

• The student will:
  • conduct an experiment to discover what happens to air when it is heated or cooled.
  • discover that wind moves from a high-pressure area (an area of sinking air) to a low pressure area (an area of rising air).

Estimated Time for Completing Activity:

• 40-60 minutes

Type of Activity:

• Exploratory

National Science Standards:

• Standard A Item 1

Virginia SOLs:

• Science 3.1, 4.1, 4.6, 5.1

Vocabulary:

high pressure area, low pressure area, wind, prediction, hypothesis, inflate, deflate

Materials Needed:

• Balloon
• Bottle(narrow neck)
• Two small bowls
• Hot water
• Ice water
• Paper and pencil
• Timer

Strategies and Procedures:

• Explanation: Explain that the uneven heating of the atmosphere by the Sun causes differences in temperature and air pressure. This results in varying weather.

Procedure:

1. Divide class into small groups and provide each group with the necessary materials and instructions.
2. Stretch a balloon over the neck of the bottle
3. Set the bottle in a bowl of hot water. Let the bottle stand in the water for one minute. Observe what happens. Record your observation.
4. Set the bottle in the bowl of ice water. Let the bottle stand for one minute. Observe what happens. Record your observation.
5. Discuss your observations and write a hypothesis
6. Each group will share their hypothesis with the class

Discovery and Conclusion:

• Warm air expands, becomes lighter than the surrounding air, and rises.
• Cold air is heavier than the surrounding air and sinks.

Discover and Questioning:

• This movement causes wind. Do you think that wind blows from a high pressure area to a low pressure area, or from a low pressure area to a high pressure area?
• Discussion should follow with conclusion:

  Wind moves from a high pressure area to low pressure area

Extention Activities:

• Give each student a balloon. Have the students inflate their balloons. Explain that this is like a high pressure area inside each balloon.

  Have the students let go of their balloons.

  The high pressure area inside the balloon rushes outside resulting in wind. Similarly the Earth's winds blow from high to low pressure areas
  

• Read Feel the Wind by Aurther Dorros.

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Lesson Plan submitted by Carol Mitchell, Poquoson Elementary School, Poquoson, Virginia, USA, for NASA's S'COOL Project.

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