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and Physics of Diving
| This laboratory activity is designed
for children in middle school grades sixth through eighth. Activities
aim to encourage students to find answers for themselves. The activities
include a math-worksheet, new vocabulary and the construction of learning
models. Each model fulfills a different purpose: The dive depth model
allows students to put their educated guess to workÉlater establishing
the true or false perceptions of diving capabilities of marine animals
and humans. The lung model allows students to make a lung out of plastic,
play with it, and gain an understanding of its function through introspection.
The model of the bends helps demonstrate the accumulation of nitrogen
bubbles in bones and muscles. The pressure model shows how air is
compressed when pressure is applied. At long last, the density model
points out the difference between dense and lighter materials. All
of the models are set up to be engaging, allowing students to come
up with answers to complicated scientific questions rather than just
being told the facts. These activities intend to expand the student's
knowledge on many subjects such as, math, physics, and physiology
all at once in a painless, fun and exciting manner.
description or introduction
The scientific principles
that the activity is founded on.
Scientific Principals Included in the Lesson Plan:
- Marine animals have special adaptations that allow them to
- Positive buoyancy is needed by marine animals to help them
- Humans attempt to dive deep in the ocean comes with great
difficulties totally unlike the great ease with which marine
animals take to diving.
- The human respiratory system consists of nose, mouth, throat,
trachea (windpipe), and lungs. It gets oxygen from the air via
the lungs. When one inhales, oxygen comes into the lungs. When
one exhales carbon dioxide is expelled from the lungs through
you nose or mouth. In the lungs air sacs called alveoli bring
air into contact with blood passing through tiny blood vessels.
- Decompression sickness known as "the bends" and acute mountain
sickness is brought on by the decrease in atmospheric pressure.
- Pressure increases with depth and decreases with altitude.
- Terrestrial organisms are under 1 atmosphere of pressure.
Pressure increases 1 ATM with every 33ft (about 10m) of water.
Marine organisms are under more pressure because water is denser
than air. Density equals mass divided by volume.
- Cooling seawater becomes denser whereas, freshwater becomes
less dense as it cools.
Diving capability of marine animals is amazing. For example, the
emperor penguins can dive approximately 700 meters, weddell seals
1000 meters, elephant seals 1,800 meters, and sperm whales 2,200
meters. These diving capacities are achieved through adapted mechanisms
they have for deep-sea dives. Some of these mechanisms include:
faster breathing, circulating blood exclusively to the brain and
heart, streamlining of their bodies, having heavy bones, collapsible
lungs, and more hemoglobin/myoglobin proteins for oxygen transport.
On the contrary, to increase buoyancy some marine animals substitute
light ions for heavy ones in internal fluids, store lipids, or have
Humans lack the adaptive mechanisms mentioned and can not deep-sea
dive with the same great ease or performance seen in marine animals.
One of the many mechanisms that humans lack is the spontaneous collapsible
lung seen in marine animals. Humans have a lung with a rib cage
and diaphragm that moves in rhythm to breathing. Breathing allows
flow of oxygen from the nose or mouth to the trachea, bronchial
tubes and ultimately the lungs. Each bronchial tube goes into a
lung and continues to branch into smaller tubes. The smaller tubes
end in air sacs called alveoli. Capillaries surround alveoli where
oxygen exchange takes place. Although, human lungs are magnificent,
they are not well suited for deep-sea diving. Largely, humans must
then contend with their physical constraints. The pressure at depth
is so massive that it can collapse a human lung and force all remaining
oxygen out. Worst of all when a diver ascends to the surface the
decrease in pressure can cause decompression sickness, known as
"the bends". " The bends" cause nitrogen bubbles to amass in the
bones and muscles causing severe pain. Similarly, increasing altitude
often produces acute mountain sickness (AMS) causing headaches,
shortness of breath, nausea, and dizziness. All of these symptoms
stem from a lower oxygen pressure.
Pressure is the acting force on a unit area. Terrestrial organisms
are under 1 atmosphere (ATM) of pressure. Pressure increases 1 ATM
with every 33 ft (approx.10m) of water. Marine organisms are under
more pressure because water is denser than air. Higher pressure
is related to greater density. Density grows as unvarying mass is
confined to a smaller volume. In fact, seawater becomes denser as
it cools given that molecules move slower and pack closer together.
Freshwater does the opposite it becomes denser as it cools and then
at 4C and below it freezes and expands. The expansion causes molecules
to take up less space resulting in lighter ice. To summarize, seawater
becomes denser as it cools while freshwater becomes lighter.
for the activity
- Math-worksheetÉ. Original idea by Elena Ruiz with help from
- Dive Depth ModelÉ.Original idea by Elena Ruiz, derived from
looking at pangea model in marine biology classroom.
- Lung ModelÉ. Idea from a science book provided by Dr. Mangin.
I forgot to ask for the information like author, title and publication
- The model of the bendsÉ.Idea from the "Big Blue Ocean" by Bill
Nye, Copyright- September 1999 by Little Bear Company in co-operation
- The pressure modelÉ.Idea from the Marine Biology Classroom.
- The density modelÉ. Idea from College Physics Text by Jerry
D.Wilson,Copyright-1994 Prentice-hall, Inc.
time to do the activity
|Understand the underlining adaptations
that allow marine animals to deep-sea dive.
|Understand how lungs function.
|Understand what causes the bends
and mountain sickness
|Understand math and physics behind
Science Education Standards. (NSES)
content standards that this lesson plan covers:
|Life Science Content Standard
For grades 5-8
Structure and living systems
"The human organism has systems for digestion, respiration , reproduction,
circulation, excretetion, movement, control, and coordination, and
for protection for protection from disease. These systems interact
with one another."---This lesson plan covers human respiration.
|Life Science Content Standard
For grades 5-8
Diversity and adaptation of organism
"Biological evolution accounts for the diversity of species developed
through gradual process over many generations. Species acquire many
of their unique characteristics through biological adaptation, which
involves the selection of naturally occuring variations in populations.
Biological adaptations include changes in structure, behaviors, or
physiology that enhance survival and reproductive success in a particular
environment."------The lesson plan covers marine animals mechanistic
adaptations for deep-sea diving.
- Dive Depth Model-Cut out pictures of the following: human diver,
northern fur seal, bottlenose dolphin, emperor penguin, weddell
seal, leatherback sea turtle, northern elephant seal, sperm whale.
- Construction paper,
- Access to chalkboard,
- chalk and sticky magnet tape or double-sided tape.
- Lung Model-2L plastic bottle,
- three-way hose connector,
- modeling clay,
- 2rubber bands,
- plastic tube,
- 3 small balloons and scissors.
- The Bends Model-two six pack unopened plastic 16oz soda bottles,
- access to place where there is no fret of making a mess preferably
- Pressure Model- 2L soda bottle,
- 1.75L of water,
- 1ml glass vial.
- Density Model- 12 oz unopened Classic Coke Can and Diet Coke
- 10-15 gallon fish tank,
- 10-15 gallons of water.
- Math worksheet-scratch paper and pencil.
|Have all materials ready to
use. Attempt to make and use all of the models before hand. For the
dive depth model make sure that all of your pictures are cut out,
glued unto construction paper and that the sticky magnet/double-sided
tape works. In addition, to having clearly marked on the chalk board
a scale showing depth of the ocean by 200m increments. Then students
forming groups of four can construct the lung model. Following bends
model experiment should be carried out in a place where there is no
fret of making a mess by students in-groups of two. Prior to class
the instructor should build the pressure model due to the time consuming
and tricky set up. Finally, the density model should have an appropriate
sized fish tank of about 10-15 gallon filled with water and ready
to go. The math worksheet explaining pressure and density can be consulted
throughout the class period. In short, be prepared and don't forget
to have fun.
Procedure for the Activity
The dive depth model- Cut out picture of the following, human diver,
northern fur seal, bottlenose dolphin, emperor penguin, weddell
seal, leatherback turtle, northern elephant seal, sperm whale. These
pictures can be found in magazines or in the internet. Once pictures
have been found and cut out then they can be glued unto construction
paper. On the backside of the construction paper apply a small piece
of sticky magnet or double- sided tape. The chalkboard should be
marked showing a scale starting at 200m- 2200 m with noted increments
of 200m. The model is now ready for use and students can put the
pictures on the chalkboard based on their educated guess as to the
different deep-sea diving capacities of the human and marine animals.
The following are the approximate diving capacities: human diver
200m, northern fur seal 400m, bottlenose dolphin 700m, emperor penguin
700m, weddell seal 1000m, leatherback turtle1300m, northern elephant
seal 1800m, sperm whale 2200m.
The lung model-Place the plastic tube around the opening of the
hose connector. Use the modeling clay to make an airtight seal.
Then put the two balloons around the other openings of the hose
connector and secure them with rubber bands. Check to see if the
link between the connector and the balloons is airtight. Next using
scissors, make a smooth cut off the bottom of the plastic bottle.
Place the balloons and connectors inside the bottle and with modeling
clay fasten the hose connector and plastic tube to the neck of the
bottle. Again, make sure to have an airtight seal. Afterward, tie
a knot in the neck of the third balloon and cut it crosswise in
half. Stretch the knotted part of the balloon over the lower end
of the bottle. Secure the balloon as tight as possible so that is
resembles a drum skin. The balloon at the bottom represents the
diaphragm. Finally, hold the balloon its knot and pull it down.
The diaphragm also moves down when you inhale lowering the air pressure
inside the lungs and causing air to be sucked in from the outside.
The other two balloons should expand, just like your lungs.
The model of the bends- Get an unopened 16oz-soda bottle that contains
carbonated soda. Shake it up vigorously twists the cap gently letting
a bit of air escape then twist the bottle cap shut and airtight.
Observe the bubbles forming inside the soda bottle. This illustrates
the accumulation of nitrogen bubbles in the tissues that cause the
bends in human divers.
The pressure model-Obtain an empty 2L-soda bottle and fill it with
1.75L of water. Then place a small glass vial inside upside down
letting some water enter it. Next cap the soda bottle airtight.
Squeeze the soda bottle and observe how the glass vial moves up
and down. Notice how the glass vial fills with more water and less
air as the soda bottle is squeezed. This illustrates how air is
compressed when pressure is applied.
The density model- Obtain an unopened 12oz can of Classic Coke
and one of Diet Coke. Put the soda cans into a 10-15 gallon tank
full of water. Notice how the Classic Coke sinks and the Diet Coke
floats. This takes place because the density of the Diet Coke is
less than that of the water, while the Classic Coke has a greater
density. This helps in understanding density and also buoyancy.
work sheets, additional web pages
for discussion or conclusion
|What are other cool things
that marine animals do that humans cannot do?
|What ideas do you have to
improve research in the depth of the ocean?
|What are animals that live
in the different depth layers of the ocean? Why do they live there?
How do they live there?
|At the end of the lesson plan
students should be able to: Name a couple of things that help make
marine animals better suited for deep sea diving. Tell about lung
function, the bends and acute mountain sickness. In addition to, fully
understanding the concept of pressure and density. Some questions
one could ask through out the activity or as a form of evaluating
their progress are the following: What mechanism do marine animals
have for deep-sea diving that humans do not have? What is atmospheric
pressure, and what is it in the mountains vs. the deep seaÉdoes it
increase or decrease? How do our lungs work? Do we breathe oxygen
or carbon dioxide? Is seawater denser as it cools or as it heats?
Is ice more or less dense than liquid water? Why? What are the bends?
Overall, children should enjoy all of the activities and be allowed
to explore the possible answers to the scientific topics discussed.
Learning perhaps that science is logical, Comprehensible and really
activities which relate to and extend the complexity of the experiment.
A web address with information on the topic of the activity.
|Magazine: American Scientist,