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This
activity page will offer:
-
A hands-on experience in streamline design
- An
opportunity to design, build, test, and improve design ideas
- A
hands-on (and hands-wet) construction activity
MATERIALS
- Trough
(a plastic gardening one will do)
- Waterproof
tape
- Small
toy car or similar toy
- Straw
- Scissors
- Waterproof
clay
- Aluminum
foil
- Weight
- Fishing
line
- Stopwatch
- Water
PROCEDURE
- Obtain
a long, plastic trough. If necessary, use waterproof tape
to seal up any drainage holes in the container.
- Position
the trough on a sturdy tabletop so that one end aligns with
the edge of the table.
- Use
a scissors to cut two small segments of straw. These segments
will be used as guides for the fishing line.
- Place
one segment in a small lump of waterproof clay. Set the
clay at the bottom of the trough as shown in the diagram.
- Place
the other segment of the straw in another lump of clay.
Position this lump on the edge of the trough as shown in
the diagram.
- Obtain
a one-meter length of fishing line. Thread the line through
both straws.
- Tie
one end of the line to a small weight. Use waterproof tape
to attach the other end to a small car or similar toy.
- Fill
the trough with water so that the car is submerged.
- Position
the car at the far end of the trough with the weight raised.
- Release
the weight. Use a stopwatch to determine how long it takes
for the car to travel across the trough.
- Perform
several trials to obtain an average time.
-
Use a small lump of clay to secure a deflection screen onto
the front end of the car as shown here. The screen should
be made of a piece aluminum foil.
-
Perform several trials to obtain an average time. Experiment
by using different dimensions of this shield. How does this
effect the pull-time?
- Use
two pieces of aluminum foil to create a plow-like blade
that can be added to the front of the vehicle.
- Perform
several trials to obtain an average time.
- Try
working a piece of waterproof clay into the shape of a bullet.
Add this shape to the front of the car as shown below. Make
sure that the clay does not interfere with the spin of the
wheels.
- Perform
several trials to obtain an average time.
Questions
-
What force powered your underwater vehicle? Explain.
- How
did the shield you added to the car affect its original
speed? How does the attachment point affect the performance?
- How
did adding a plow-like blade to the vehicle affect its movement?
Why?
- Did
adding the extra weight of the clay improve or reduce the
speed of the car? Explain.
Critical
Thinking
Do
you think that the car, without the plow-like blade, would
have moved faster if it was moving through air instead of
water? How would streamlining have affected the car in this
case? Explain.
EXTENSIONS
Streamlined Shapes
How
is streamlining applied to the shape of automobiles? Examine
illustrations of different types of cars. Compare and contrast
their shapes. More specifically, examine the shape of racecars
with the shape of minivans. What are the advantages and disadvantages
of each design? What characteristics identify a streamlined
shape?
Announcing
a Submarine Race
Work
with a partner. Create a fictional script about a pair of
radio personalities delivering commentary on a human-powered
submarine race. Keep the dialog humorous, but integrate actual
facts about the submarines.
Art
Connection
Imagine
designing your own human-powered submarine. What shape would
the vehicle be? How would it be powered? Think about it. Then,
draw a set of scale blueprints. Identify the parts of your
vehicle and the mechanical actions essential to its movement
and control.
WEB
CONNECTION
Of
Boats and Waves
http://members.iinet.net.au/~bluep/wavedrag.html
Information about the physics of hull design for surface ships.
Turtle:
A Revolutionary Submarine http://www.geocities.com/Athens/Acropolis/4870/
DrGeorgePCPage9Turtle.html
Learn about the first US human-powered submarine.
Bibliography
of Human-Powered Submarines Articles
http://scilib.ucsd.edu/sio/indexes/subbibl.html
Teaching
Guide from the FRONTIERS Archive http://www.pbs.org/safarchive/4_class/45_pguides/
pguide_403/4543_sub.html
Check out these activities related to our earlier coverage
of the human-powered submarine race.
The
activities in this guide were contributed by Michael DiSpezio,
a Massachusetts-based science writer and author of "Critical
Thinking Puzzles" and "Awesome Experiments in Light & Sound"
(Sterling Publishing Co., NY).
Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools,
Wayland, MA
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools,
Cambridge, MA
Anne E. Jones, Science Department, Wayland Middle School,
Wayland, MA
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