Balloon Design Challenge
Students design and make a hot air balloon using a plastic
bag. They measure the time it stays in the air and its
distance from the launch point.
Students will understand how to convert time and distance
Standards Addressed — Mathematics
Use Measurement Techniques and Tools, Benchmark B
05. Make conversions within the same measurement system
while performing computations.
Divide the students into
groups of two or three.
Have available various types
of plastic bags, string and paper clips. Following
are some guidelines:
Dry-cleaning bags work the best
because they are the lightest, but
all types should work
Students can use paper clips around the
bottom to keep some balance
use string to tie off the top if they
are using a dry-cleaning bag
one or two people hold the bag while the other teammate
blows hot air
into the bottom
dryer. The students should hold the bag
until they feel a tug
on the material. It is helpful to gather
the bottom of the balloon so that the hot
Students should measure in seconds
(and convert to minutes) the time from when
they release the
balloon until any part
of it touches the ground. Students should
further measure the distance from the
launch site to
the landing site
in centimeters (and convert to meters).
is a good idea to do this activity outside (if electricity
go as high as
the second story of a school. Indoors,
the balloons can generally hit the
Extension: Older students can use
a clinometer to determine the actual
that the balloon
on making a clinometer, go to the School
Yard Clinometer Web site at www.state.nj.us/dep/seeds/syhart/clinom.htm.
The string on the clinometer will show
tangent angle: Tan = Opposite/Adjacent.
Connection: “When air or any other
gas gets hot and expands, it gets less dense
the same amount of air occupies a larger
space. Hot air balloons fly because they contain warmer,
The air in the balloon, being warm,
is less dense (lighter) than the cool air around it so
upward, like a
cork in water. When the air gets cool,
the balloon will sink again.” (Source: NASA)
||Balloon is well-designed and constructed.
||Balloon flies well but has some problems.
||Balloon needs some design changes.
||Balloon didn’t fly.
||Group worked very well together, with each person
doing a part of the task.
||Group worked well together, but some members were
not as involved as others.
||Group had some problems working together. Some members
were not involved.
||Group was dysfunctional.
||Both the time and distance measures, and their conversions,
||Both the time and distance measures were accurate,
but the conversion had an error.
||Either the time or distance measure was inaccurate.
The conversion had an error.
||Measures were inaccurate.