Return to Physics Index
Lisa C. Ingram Frederick Douglass Middle Academy
543 N. Waller
Chicago IL 60644
To understand the existence and movement of air. Designed for grades 5 through 8.
a piece of paper
Teacher will walk around the room with an air cannon. Teacher places items on
top of the head of someone and knocks it over with the air cannon. Teacher hits
the air cannon, so that air will touch someone. Teacher will ask students, what
is inside of this object? Wait for responses. Talk to students about air being
everywhere. That it is all around you, even things that look as if they are
empty are really full of air.
Experiment 1: Teacher will tape two apples on strings from a door frame or from
something else. They should hang about 3cm (1in) apart, and level with your
mouth. Wait until the apples are steady then blow hard between them.
Question? Do the apples move apart or together? Why?
Answer: When you blow, you make air between the apples move. This moving air
has less pressure than the still air on either side of them. So the still air
pushes the apples together.
Experiment 2: Teacher will hold a plastic bag open, pull it through the air to
trap some air in it, then close it. Tell the students that you can't see the
air in the bag but you can feel how firm and squashy it is.
Question? If you have an empty bag, does it have air in it?
Answer: Yes, air is everywhere, even though you can't see it.
Experiment 3: Teacher will put bits of kleenex on a flat surface and drop a
book on them. The bits of paper blow away because the falling book pushes air
out of the way and makes a wind.
Question: Does air move things?
Answer: Yes, air moves and vibrates things.
Experiment 4: Teacher explains that air not only moves things, it can also slow
things down that move through it. Ask two volunteers to come up and stand on
chairs. Below them place a wide bowl. Hand each student some playing cards.
Have one student drop their cards end up. Have the other student drop their
cards face down.
Question? Which cards fell in the bowl the most? Why?
Answer: The cards dropped faced down usually landed in the bowl because the air
pushing up beneath it escapes fairly evenly all around it, so it falls straight
down. The card dropped end up, swoops to one side.
Experiment 5: The teacher will take an empty glass (let the students observe
the empty glass) and submerge it into water. The teacher will ask students to
predict whether or not the paper inside the glass will get wet or not.
Question? Why didn't the paper get wet?
Answer: The air keeps nearly all the water out. (Teacher can tilt the glass to
show water going into the cup)
Experiment 6: The teacher will divide the class into groups of a number that
will vary. Each group will be given an air cannon. Inside the air cannon will
be a colorful smoke bomb. Each group will go in an open area and take turns
shooting their air cannons. All students should observe the colorful smoke
rings, which are air.
Students will list 3 things that they have learned about air.