Air Pressure Investigation #2
Space Bag
Articulating a Vision of Effective
Science Instruction
Purpose
To engage in the practices of science
to deepen understanding of
effective science instruction
What we are going to do
• Function as a community of learners
• Investigate air pressure phenomena as
adult learners to deepen knowledge of
science teaching and learning
• Apply the Air Puppies Model to explain
two air pressure demonstrations
Reflection
• Think about the Air Puppies model – 2 rooms
and a frictionless movable wall
• Think about your investigation of the balloon
in the bottle using the Air Puppies model to
construct explanations for your observations
How did the model help you understand
what you observed in the activity?
New Air Pressure Investigations
1. Two demonstration videos
2. Predict what you think will happen
based on your prior knowledge about
the Air Puppies model
3. Use the model to explain the
observations in each demonstration
4. Identify similarities and differences in
the two demonstrations
Air Pressure Model Review
1. “Air Puppies” represent molecules of gas
2. Just as puppies move randomly and quickly
often bumping into walls and each other, so
do gas molecules
3. Two rooms with Air Puppies are divided by
a frictionless, movable wall
4. In each room, Air Puppies move freely and
bump into all 4 walls of the room
Air Pressure Model Review
Air Pressure Phenomenon:
The “Space Bag”
• The setup will be shown first, then
paused to let you predict the outcome
• Materials include:
 A commercial vacuum storage bag
known as a “space bag”
 A comforter inside the space bag
 A vacuum cleaner with hose
Air Pressure Phenomenon:
The “Space Bag”
Air Pressure Phenomenon:
The “Space Bag”
In your journal
• Predict what you think will happen
as the vacuum cleaner hose remains
attached to the Space Bag
• Note why you think that will happen
• How can the Air Puppies model help
you make a prediction?
Air Pressure Phenomenon:
The “Space Bag” – Action
Developing an Explanation
for the Space Bag Demo
• With a partner, develop an explanation using
the Air Puppies Model
• Write your explanations in your journal
• Draw Air Puppy diagrams that represent the
situation a) before the vacuum was turned on
and b) after the vacuum was removed
• Identify the movable wall and the two rooms it
separates
Developing an Explanation
for the Space Bag Demo
What do the two rooms represent?
The space inside the bag and the
atmosphere outside the bag
What represents the movable wall?
The plastic bag itself
Developing an Explanation
for the Space Bag Demo
How can the Air Puppies model be modified
to include the vacuum cleaner and hose?
The vacuum cleaner can be represented
by a pump that moves air puppies from
one room [in the bag] into the other
room [the atmosphere outside]
Developing an Explanation
for the Space Bag Demo
Modified diagram: (Before vacuum cleaner is turned on)
Developing an Explanation
for the Space Bag Demo
Modified diagram: (Vacuum cleaner is turned on)
Air Pressure Phenomenon:
The “Human Shrink Wrap”
• The setup will be shown first, then
paused to let you predict the outcome
• Materials include:
 A person
 A large “human size” plastic bag
 A vacuum cleaner with hose
Air Pressure Phenomenon:
The “Human Shrink Wrap” - Setup
Air Pressure Phenomenon:
The “Human Shrink Wrap”
In your journal
• Predict what you think will happen as the
vacuum cleaner hose remains attached to
the Shrink Wrap
• Note why you think that will happen
• How can you use the Air Puppies model to
help you make a prediction?
Air Pressure Phenomenon:
The “Human Shrink Wrap” - Action
Developing an Explanation
for the Human Shrink Wrap Demo
• With a partner, develop an explanation using
the Air Puppies Model and record in your
journal
• Draw Air Puppies diagrams that represent the
situation a) before the vacuum was turned on
and b) after the vacuum was removed
• Identify similarities and differences between
the Space Bag and Shrink Wrap demos
Developing an Explanation
for the Human Shrink Wrap Demo
What do the two rooms represent?
The space inside the bag and the
atmosphere outside the bag
What represents the movable wall?
The plastic bag itself
Developing an Explanation
for the Human Shrink Wrap Demo
How can the Air Puppies model be modified
to include the vacuum cleaner and hose?
The vacuum cleaner can be represented
by a pump that moves air puppies from
one room [in the bag] into the other
room [the atmosphere outside]
Developing an Explanation
for the Human Shrink Wrap Demo
Modified diagram: (Before vacuum cleaner is turned on)
Developing an Explanation
for the Human Shrink Wrap Demo
Modified diagram: (After vacuum cleaner is turned off)
Similarities & Differences
Between Air Pressure Demos
Similarities
Two rooms - inside the
bag and the atmosphere
outside
Movable walls are the
plastic bags
Differences
Comforter is porous with air
between fibers that can be
removed. Human is solid
and can’t be compressed.
No one-way valve on shrinkwrap bag, so air re-enters
bag after vacuum is turned
off
Similarities & Differences
Between Air Pressure Demos
Similarities
Vacuum cleaners are the
pumps that move air
particles (puppies) from one
room to the other room
Neither comforter nor human
can be moved inside the bag
Differences
The two rooms have
different sizes
What Makes Science Instruction
Effective? Part IV (cont.)
Analyzing Science Teaching and
Learning