New Rocket Guide 6 15 08.indd
Rocket Activity
Water Rocket
Construction
Objective
Student teams will construct water rockets and
successfully launch them.
Description
Using plastic soft drink bottles, cardboard or
Styrofoam food trays, tape, and glue, small
teams of students design and construct
rockets. A simple assembly stand assists
them in gluing fi ns on their rockets, and a nose
cone is mounted on the top. A small lump of
National Science Content Standards
modeling clay is inserted into the nose cone
Physical Science
to enhance the rocket’s stability in fl ight. The
• Position and motion of objects
rocket is launched with a special launcher. The
• Motions and forces
plans for the launcher are found in the Water
Science and Technology
Rocket Launcher activity.
• Abilities of technological design
National Mathematics Content Standards
• Geometry
Materials
• Measurement
2-liter soft drink bottle (1 per team)
Styrofoam food trays
National Mathematics Process Standards
Posterboard, cardboard
• Connections
Masking tape
Low-temperature glue guns and glue
1- to 2-inch piece of 1/2” PVC pipe
4X4X1-inch board (per team) and small
screw and washer
4 ounces of clay
Safety goggles
Plastic grocery sacks or thin fabric scraps
String
Sandpaper or emery boards
Art supplies
Water rocket launcher (see page 109)
Bicycle pump or small compressor
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Management
for constructing water rockets through launch
Begin collecting 2-liter soft drink bottles a few
and reporting. Student teams form rocket
weeks before the activity. Save the caps, too.
companies and compete for government
Rinse the bottles and remove the labels. There contracts. The procedures that follow here
will be some glue adhesive remaining on the
should be used for the construction phase of
bottle. Goo remover can be used to clean it off, Project X-51.
but it tends to smear the surface.
Construct assembly stands out of small
Background
blocks of wood. Attach a bottle cap to the
A water rocket is a chamber, usually a 2-liter
middle of each board with a small screw and a
soft drink bottle, partially filled with water. Air
washer through the cap. When students begin
is forced inside with a pump. When the rocket
constructing their rockets, they screw the bottle is released, the pressurized air forces water out
neck into the cap, and the board below will hold the nozzle (pour spout). The bottle launches
the rocket upright for gluing. The blocks also
itself in the opposite direction. The bottle
make a convenient way of storing the rockets
usually has a nose cone for streamlining and
upright when not being worked on.
fins for stability.
Water rockets are easily capable of 100-
meter-high flights, but advanced hobbyists have
combined bottles and staged bottles for flights
over 300 meters high.
Water bottle rockets are ideal for
teaching Newton’s laws of motion. The launch
of the rocket easily demonstrates Newton’s
Make mounting stands by screwing the plastic
third law. Students can see the water shooting
bottle caps to a board. Use a washer for
out of the nozzle (action) and see the rocket
added strength.
streak into the sky (reaction). Students can also
experiment with different pressure levels inside
Pre-cut the PVC segments. The cuts can the chamber and different amounts of water.
be slanted to streamline them. A saw or PVC
The rocket will not fly very high if it is filled only
cutter is used for cutting. The segments act as
with air. The air will quickly rush out during the
launch lugs to guide the rocket up the launch
launch, but its mass is very low. Consequently,
rod during the first moments of the rocket’s
the thrust produced is also low (Newton’s
skyward climb.
second law). By placing water in the bottle, the
Be sure to use low-
air has to force the water out first before it can
temperature glue guns. High-
leave the bottle. The water increases the mass
temperature guns will melt
expelled by the rocket, thereby increasing the
the plastic bottle. A small
thrust.
dish of ice water in a central
Like all rockets, the flight performance
location is helpful for students
of water bottle rockets is strongly influenced
who get hot glue on their
Launch lug with
by the rocket’s design and the care taken in its
slanted cuts.
fingers. Immersing the fingers
construction. Beveling the leading and trailing
will immediately chill the
edges of fins allows them to slice through the
glue. Do not put bowls of water near the guns
air more cleanly. Straight-mounted fins produce
themselves because the guns use electricity
little friction or drag with the air. A small amount
for heating, and shorting could occur if they get of ballast weight inside the nose cone helps
wet.
balance the rocket. This moves the center of
mass of the rocket forward while still leaving a
Special Note The activity entitled Project X-
large fin surface area at the rear. In flight, the
51 (see page 118) lays out an entire process
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rocket design acts like a weather vane, with the 7. Have teams glue
nose cone pointed up and the fi ns down.
launch lugs to the
side of the rocket
Procedure
midway up the body
1. Set up a supply station with materials such
of the rocket and
as Styrofoam food trays, posterboard, tape,
position it midway
sandpaper, and art supplies.
between two fi ns.
2. Set up a gluing station with several heated
8. Challenge teams to
low-temperature glue guns and extra glue
think up a way to
sticks.
add a parachute to
3. Divide students into teams for constructing
their rockets for soft
rockets. If using Project X-51, describe the
landings. Plastic
project to them and explain its objectives.
grocery bags or
Discuss construction techniques for their
lightweight fabric
rockets. Give each team an assembly stand
scraps can be cut
and a 2-liter soft drink bottle. Project X-51
to make parachutes
Launch Lug
requires teams to keep track of the materials
and strings can be
they used. Even if they are not doing the
used to attach them.
project, it is still good for teams to account
The nose cone must
for the materials used.
remain in place until
4. Show teams how to use the glue guns and
the rocket reaches the top of its fl ight; then it
point out the cold water dish in case glue
should open and release the parachute.
gets on fi ngers. Students should wear safety
goggles when gluing.
5. Describe how fi ns can be smoothed with
sandpaper to slice through the air with little
drag.
6. Remind teams to add clay to the inside of
their nose cones.
Trim fi n edges with sandpaper to give them
knife-blade shapes to slice through the air.
The Assembly Stand supports the rocket
while it is being constructed.
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9. When the rockets have been completed,
Assessment
have teams qualify their rockets for fl ight by
• Inspect each team’s rocket for the
conducting string tests. Using several feet
construction skill employed. Fins should be
of string, tie the rocket around the middle so
vertical and securely attached. The rocket
that it balances. Because of the nose cone
should be stable.
weight, the balance point will be towards the
• Observe the fl ights and note how the recovery
nose. When the rocket hangs level, a small
system designed by teams worked.
piece of tape should be temporarily fi xed to
the string and bottle to keep the string from
Extensions
slipping. The rocket is then twirled in a circle. • Conduct a space art show to feature
If the rocket tumbles while circling, it is not
decorating schemes of team rockets. Have
stable and needs more nose cone weight,
students draw artist’s conceptions of their
bigger fi ns, or a combination of both. If the
rockets in fl ight. (See The Art of Spacefl ight
rocket circles with the nose always pointed
on page 146). To view artist’s conceptions
forward, it is stable and ready for fl ight.
of NASA’s new Constellation program, see
(More information about string tests will be
pages 13-17.
found in the instructions for Project X-51.)
Clear an open space for swing tests.
10. Review launch procedures with the teams.
The instructions are outlined in the activity
for constructing a water rocket launcher (see
page 109). Conduct an inspection the day
before the launch to ensure that rocket fi ns
are securely attached.
11. Set up a tracking station for measuring the
altitudes achieved by the rockets. Follow
all safety procedures and instructions when
launching the team rockets.
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