Diving Physics
Quiz settings
Property
Setting
Passing score
80%
Display Point Value
Yes
Randomize Questions
Yes
Total Number of Questions
20
Total Number of Questions to Ask
All
Display User Score
Yes
Display Passing Score
Yes
Display Pass/Fail Messages
Yes
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Questions
Multiple Response, 10 points, 1 attempt(s) permitted.
1. Select all that apply to "atmospheric pressure". There are at least three correct answers. (Select
all that apply to atmospheric pressure)
Correct
Choice
X
14.7 psi
X
decreases with altitude
X
1 atm
the force acting on a unit area
increases with water depth
pressure due to the weight of water
the pressure exerted by a single gas in a mixture
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
2. Select all that apply to "hydrostatic pressure". There are at least four correct answers.
Correct
Choice
the force acting on a unit area
X
.445 psi per foot seawater
X
increases with water depth
X
pressure due to the weight of water
X
.432 psi per foor freshwater
the sum of atmospheric and absolute pressures
the pressure exerted by a single gas in a gas mixture
decreases with altitude
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
3. Select all that apply to "absolute pressure. There are at least three correct answers.
Correct
Choice
X
the sum of atmospheric and hydrostatic pressures
X
increases with water depth
X
ata
the difference between atmospheric pressure and the pressure being measured
pressure due to the weight of water
the pressure exerted by a single gas in a gas mixture
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
4. Select all that apply to "gauge pressure. There are at least three correct answers.
Correct
Choice
X
the difference between atmospheric pressure and the pressure being measured
X
ata minus 14.7
X
increases with water depth
the sum of atmospheric and hydrostatic pressure
the pressure exerted by a single gas in a gas mixture
the force acting on a unit of area squared
.432 psi per foot seawater
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Choice, 10 points, 1 attempt(s) permitted.
5. As depth increases the ______ of the breathing gas increases.
Correct
Choice
Feedback
X
density
Correct
specific gravity
Incorrect, as depth increases, the density of
the breathing gas increases and becomes
heavier per unit volume.
pH
Incorrect, as depth increases, the density of
the breathing gas increases and becomes
heavier per unit volume.
volume
Incorrect, as depth increases, the density of
the breathing gas increases and becomes
heavier per unit volume.
True/False, 10 points, 1 attempt(s) permitted.
6. Specific gravity is the ratio of the weight of a given volume of a substance (density) to that of an
equal volume of another substance.
Correct
X
Choice
True
False
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
7. Select all that apply to "freshwater". There are at least three correct answers.
Correct
X
Choice
has a density of 62.4 pounds per cubic foot
has a density of 64 pounds per cubic foot
X
freezes at 32 degrees F (0C), and boils at 212 degrees F (100C).
X
in its purest form, is a poor conductor of electricity
contains almost every substance known
is a good conductor of electricity
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
8. Select all that apply to "seawater". There are at least three correct answers.
Correct
Choice
has a density of 62.4 pounds per cubic foot
X
has a density of 64 pounds per cubic foot
freezes at 32 degrees F (0 C)
in its purest form, is a poor conductor of electricity
X
contains almost every substance known
X
is a good conductor of electricity
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Choice, 10 points, 1 attempt(s) permitted.
9. One meter equals 3.28 feet. Convert 25 feet to meters.
Correct
X
Choice
Feedback
7.62
Correct
82
Incorrect, to convert feet to meters divide feet
by 3.28
6
Incorrect, to convert feet to meters divide feet
by 3.28
25
Incorrect, to convert feet to meters divide feet
by 3.28
Multiple Choice, 10 points, 1 attempt(s) permitted.
10. One meter equals 3.28 feet. Convert 50 meters to feet.
Correct
X
Choice
Feedback
164
Correct
15.24
Incorrect, to convert meters to feet, multiply
meters by 3.28
150
Incorrect, to convert meters to feet, multiply
meters by 3.28
50
Incorrect, to convert meters to feet, multiply
meters by 3.28
Matching Drag and Drop, 10 points, 1 attempt(s) permitted.
11. Match the English and International temperature scale with its absolute temperature
counterpart. (Match the English and International temperature scale with its absolute
temperature counterpart.)
Choice
Match
Fahrenheit
Rankine
Celsius
Kelvin
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Matching Drag and Drop, 10 points, 3 attempt(s) permitted.
12. Match the choice with its definition.
Choice
Match
Archimedes' Principle
Any object wholly or partly immersed in a fluid is
buoyed up by a force equal to the weight of the fluid
displaced by the object.
Boyle's Law
For any gas at a constant temperature, the volume of
the gas will vary inversely with the pressure.
Charles' Law
For any gas at a constant pressure, the volume of the
gas will vary directly with the absolute temperature or
for any gas at a constant volume; the pressure of the
gas will vary directly with the absolute temperature.
Dalton's Law
The total pressure exerted by a mixture of gases is
equal to the sum of the pressures of each of the
different gases making up the mixture, with each gas
acting as if it alone was present and occupied the total
volume.
Henry's Law
The amount of any given gas that will dissolve in a
liquid at a given temperature is proportional to the
partial pressure of that gas in equilibrium with the
liquid and the solubility coefficient of the gas in the
particular liquid.
General Gas Law
A combination of Charles’ and Boyle’s laws; it is used
to predict the behavior of a given quantity of gas when
changes may be expected in any or all of the variables
(pressure, temperature, volume).
Positive Buoyancy
When the weight of the displaced fluid is greater than
the submerged object.
Negative Buoyancy
When the weight of the displaced fluid is less than the
weight of the submerged object.
Neutral Buoyancy
When the weight of the object is equal to the weight
of the fluid displaced.
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Response, 10 points, 1 attempt(s) permitted.
13. Select all that apply to "air". There are at least two correct answers.
Correct
Choice
X
the most common gas breathed underwater
X
it is composed of approximately 78% Nitrogen, 21% Oxygen, and 1% other gases
has a major role in decompression
is a natural by-product of metabolism
is produced by incomplete combustion of fuels and is found in the exhaust of internalcombustion engines and overheated oil-lubricated compressors
is required for human life
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Matching Drag and Drop, 10 points, 3 attempt(s) permitted.
14. Match the gas with its characteristic.
Choice
Match
Oxygen
is required for human life
Nitrogen
has the major role in decompression; as the partial
pressure increases with depth, it produces an
intoxicated state that is characterized by loss of
judgment and disorientation
Helium
is used extensively in deep diving; it has a lower
density that reduces breathing resistance;
disadvantages include “Donald Duck” voice and heat
loss due to its high thermal conductivity
Carbon Dioxide
is a natural by-product of metabolism; can cause
unconsciousness that can be fatal in divers; elevated
levels may further predispose a diver to nitrogen
narcosis, oxygen toxicity, and decompression sickness
Carbon Monoxide
a poisonous gas which interferes with the blood’s
ability to carry oxygen; is produced by the incomplete
combustion of fuels and is found in the exhaust of
internal-combustion engines and overheated oillubricated compressors
Argon
has narcotic properties and a density that make it
inappropriate as a breathing gas; is frequently used to
inflate dry suits because its higher density reduces
conduction of heat
Neon
causes less voice distortion than helium and has lower
thermal conductivity; is expensive and causes
increased breathing resistance under work load
Hydrogen
is readily available and produces less breathing
resistance at depth than other gases; its major
disadvantage is that is explosive
Feedback when correct: Correct
Feedback when incorrect: Incorrect
True/False, 10 points, 1 attempt(s) permitted.
15. Too much moisture in the diver's breathing gas can decrease breathing resistance.
Correct
Choice
True
X
False
Feedback when correct: Correct
Feedback when incorrect: Incorrect
True/False, 10 points, 1 attempt(s) permitted.
16. Humidity in the form of condensation in the breathing hoses or mask can be a problem in very
cold (freezing) conditions.
Correct
X
Choice
True
False
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Choice, 10 points, 1 attempt(s) permitted.
17. Water slows light - causing light to _______ as it enters or leaves water. This creates distortion
making objects appear larger and, at distances less than 4 feet, closer.
Correct
Choice
Feedback
X
refract
Correct
magnify
Incorrect, the correct answer is refract (bend)
be absorbed
Incorrect, the correct answer is refract (bend)
diffuse
Incorrect, the correct answer is refract (bend)
Multiple Choice, 10 points, 1 attempt(s) permitted.
18. The more dense the medium through which sound travels, the ______.
Correct
X
Choice
faster its speed
slower its speed
Feedback when correct: Correct
Feedback when incorrect: Incorrect
Multiple Choice, 10 points, 1 attempt(s) permitted.
19. _____ is the first wavelength of light to be absorbed by water.
Correct
X
Choice
Feedback
Red
Correct
Orange
Incorrect, Red is the first wavelength of light to
be absorbed by water.
Blue
Incorrect, Red is the first wavelength of light to
be absorbed by water.
Green
Incorrect, Red is the first wavelength of light to
be absorbed by water.
Multiple Choice, 10 points, 1 attempt(s) permitted.
20. One ata of hydrostatic pressure is reached every ___ feet in seawater. (One ata of hydrostatic
pressure is reached every ___ feet in seawater.)
Correct
X
Choice
Feedback
33
Correct
34
Incorrect, the correct answer is one ata of
hydrostatic pressure is reached every 33 feet in
seawater. It takes 34 feet of freshwater.
.445
Incorrect, the correct answer is one ata of
hydrostatic pressure is reached every 33 feet in
seawater. .445 is the psi increase for every foot
of saltwater descended.
.432
Incorrect, the correct answer is one ata of
hydrostatic pressure is reached every 33 feet in
seawater. .442 is the psi increase for every foot
of freshwater descended.