Lesson 5: “A Weighty Problem” and “The Balloon Trick”, from Wild About Weather
Objectives: After completing this lesson, students will be able to:
Key Question: How does air's weight and pressure affect its movement?
Time Required: 20-40 min
· balloons for each person
· 2 large balloons of equal size
· 2 yardsticks
· books or other weights
· (optional for discussion) Prentice Hall transparency: #56 Density at Two Altitudes
Procedure: See pp. 11 in Ranger Rick’s NatureScope: Wild About Weather
Assessment: Class discussion
OUSD Science Content Standards (State of California Science Content Standards):
References: National Wildlife Federation, Ranger Rick’s NatureScope, Wild About Weather. Triangle Learning Triangle Press, An Imprint of McGraw-Hill, New York, 1989, 1998.
Notes: The balloon balancing demonstration can be done quickly with a little preparation. I like to hang the meter stick balance beam from some ceiling fixture so that the whole class can easily see it. When you have the balloons roughly balanced on the beam, tape each string to the beam with a small piece of masking tape. You can fine-tune the balance by adding a few pieces of tape to one end of the meter stick. It also helps to have a few more inflated balloons at the ready to repeat the demonstration.
A more accurate conclusion from the demonstration is that the compressed air inside the balloon weighs more than the uncompressed air around it.
After the kids have done the little balloon rocket activity,
I like to keep a few balloons on the chalk tray and blow one up and release it every
time we discuss wind and air pressure.