Page 347 - NS-2 Textbook

Glossary
ABYSS-a very deep area of an ocean.
ACCELERATION -a change in velocity per unit of time.
AERODYNAMICS-the science of how objects move
through gases, especially in regard to flight.
AMMETER -an instrument to measure electric current.
AMPERE-the unit of electric current.
ANGLE OF ATTACK-the angle between the chord of a
wing and the relative wind.
ARCHIMEDES' PRINCIPLE-an object immersed in a
fluid feels an upward force equal to the weight of the
fluid being displaced by the object.
ASTEROID-any of a number of small bodies orbiting
between the planets Mars and Jupiter.
ASTHENOSPHERE-uppermost layer of Earth's mantle.
ATOLL-a ringlike coral island that encloses a lagoon.
AURORA-a high-altitude multicolored luminosity in
an atmosphere.
BALLAST -any material placed low in a vessel or bal-
loon to enhance stability or neutralize buoyancy.
BALLISTIC MISSILE-a missile that goes on a free-
falling path after a powered and guided ascent.
BATHYSCAPHE-a small research vessel designed to
operate at extreme ocean depths.
BATHYTHERMOGRAPH-a temperature- and depth-
sensing device used to record water temperatures at
various depths.
BATTERY -a device that converts chemical to electrical
energy.
BAY -a large body of water partly enclosed by land but
having a wide outlet to the sea.
BERNOULLI'S PRINCIPLE-when a fixed quantity of
fluid flows, the pressure is decreased when the flow
velocity increases.
BIODEGRADABLE-subject to breaking down or decay
by natural forces.
BIOLUMINESCENCE-light created by living organ-
isms.
BLACK HOLE-a region of space surrounding matter DRAG-fluid friction ..
so dense that not even light can escape its gravita- ECHO SOUNDER-a sonic device used to obtain water
tional pull.
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BRECCIA-fine particles of broken rocks.
BUOYANT FORCE-upward force on an object im-
mersed in a fluid.
CENTER OF BUOYANCY -the center of the submerged
portion of a body.
CENTER OF GRAVITY-the center of mass of a body;
its natural pivot point.
CENTRIPETAL FORCE-a force on a body in curved mo-
tion that is directed toward the center of curvature.
CHEMOSPHERE-the region of the atmosphere be-
tween 20 and 120 miles in altitude in which photo-
chemical reactions occur.
CONDUCTOR-materials through which an electric
charge readily moves.
CONTINENTAL SHELF -the sea bottom from the shore
to a depth of 200 meters (100 fathoms).
CORONA-envelope of gas surrounding the Sun's
chromosphere.
COSMOLOGY -the astrophysical study of the origin,
processes, and structure of the universe.
CRUISE MISSILE-an air-breathing surface-to-surface
or air-to-surface guided missile.
CRYSTAL-a three-dimensional solid structure in which
the constituent atoms or molecules are arranged in a
precise and repeating pattern.
DECIBEL (db)-unit of sound intensity level.
DENSITY-The mass of a material that is present per
unit of its volume.
DETRITUS-disintegrated matter or debris.
DIFFRACTION-bending of waves around an obstacle
as they travel.
DOLDRUMS-ocean regions near the equator charac-
terized by calms or light winds; the light winds of
these areas.
DOPPLER EFFECT -an apparent change in pitch (fre-
quency) of sound or electromagnetic waves caused
by relative motion between the source and receiver.
depths by measuring the time required for a sound