MODELING THE DIFFICULTIES
you ever played the game "Operation"? If so, you know that
this game challenged your dexterity as you manipulated metal
tongs to remove target organs. If your tongs touched the conductive
sides of a well, an alarm went off signaling an unsuccessful
operation. In this activity, your dexterity will once again
be challenged. This time, however, you'll use a metallic probe
to uncover the location of a target that represents a buried
activity page will offer:
An experience in electric circuit construction
in the difficulty in uncovering model land mines
- Aluminum foil
- Plastic food container (low sides, with cover)
- Push pin
- Four checkers
- Wooden chop stick
- Access to outdoor field that has an area of loose soil*
*The activity can also be performed indoors using a large
basin and clean, loose soil.
1- Building the Model Mine
- Work with a partner. Use a pushpin to punch a hole in
the cover and bottom of the plastic food container.
- Wrap a stack of four checkers in aluminum foil. Secure
the stack with tape. Attach a 3-ft. length of wire to the
bottom end of the checker stack and pass this wire through
the hole in both the cover and container bottom as shown
here. The checker will represent the triggering mechanism
of the land mine.
- Wrap the chopstick in aluminum foil. Attach another 3-foot
length of wire to the chopstick. Connect this wire to a
lantern battery and use another wire to attach the battery
to a buzzer. The other buzzer terminal must be connected
to the wire that comes off the land mine trigger. Here's
what the setup will look like (SEE DIAGRAM).
- Test the circuit. When the aluminum foil on the chopstick
and checker stack makes contact, the buzzer should sound.
2- Burying the Model
- If you are performing this activity outside, make sure
that the material in which you'll bury the mine is clean
and free of debris. You'll also need to loosen the soil
so that the mine can be buried and the substrate easily
- With your partner looking away, place the mine about 6
inches below the soil with the trigger mechanism facing
upwards. Bury most of the wire at this depth and let it
emerge about two feet from the mine (masking clues to the
mine's location). (See Diagram)
- If you are performing this activity inside, you'll need
to fill a large tub or container halfway with loose soil.
Place your mine in the soil - then cover it up with more
loose soil. Again, keep the wire buried so that the mine's
3- The Challenge
- Have your partner try to locate the mine using the aluminum
wrapped probe without activating the buzzer. Try mimicking
the side-probing method used by Alan in the program. If
the buzzer sounds, the "mine" has been triggered. Once the
mine has been safely located, your partner should carefully
remove it from the ground.
- Switch roles and repeat the activity.
you find the mine difficult or easy to locate? What techniques
help in locating the explosive without setting it off? Put
yourself in the role of people who actaully look for real
landmines. What types of skills would they need to complete
for a dog, the removal of land mines is a dangerous operation.
If the animal unknowingly steps on a mine or pulls a trip
cord, a deadly explosion can occur. Think about it. Do you
think that training dogs to sniff and locate land mines is
an animal rights violation or is it a fair use of animals?
How important is a dog's well being when weighed against a
if your neighborhood was mined with buried explosive devices.
How might that change your life? Think about the problems
associated with the more than one million landmines that are
have been buried throughout the world. Talk with you teacher
and discuss ways that you and your class might become active
in addressing this problem. Identify and contact local, national,
and international organizations. Find out what you can do!
(HINT: for more information, visit the Web Connection below,
or the Resources
page for this show)
an illustration that represents the molecular structure of
TNT (trinitrotoluene). Can you build it using gumdrops and
toothpicks? Remember that a carbon atom is positioned at each
of the intersections of the carbon ring structure. Think about
it. How does this structure differ from that of DNT, dinitrotoluene?
International Red Cross site on landmines
Campaign to Ban Landmines
more Web links on this topic - visit our Resources
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,
Suzanne Panico, Science Department, Fenway High School, Boston,
Anne E. Jones, Science Department, Wayland Middle School,