IDC PE 1 Flashcards
When viewed underwater, objects normally appear ____ due to ____
a. closer/ refraction
b. farther way/ visual reversal
c. larger/ turbidity
d. smaller/ conduction
a. closer/ refraction
The force of buoyancy is predicted by ____ and is an ____ force exerted on an object placed in fluid
- boyles law/ upward
- haldanes principle/ equal
- daltons law/ equal
- archimedes/ law
Archimedes law
upwards force
Your dive boat bumps into a large box floating just under the surface of a fresh water lake. after bringing aboard, you determine the weight to be 75kg. How much water does it displace?
a. 75 litres
b. more than 77 litres
c. 72.81 litres
d. less than 71 litres
a. 75 litres
INCORRECT
if an object weighing 150kg is neutrally buoyant in salt water, what is the volume of the water the object displaces?
a. 75 litres
b. 146 litres
c. 150 litres
d. 155 litres
b. 150/ 1.03 = 146 litres
1 litre = 1.03kg
10 litre = 10.3 kg
100 litre = 103.0 kg
The worst situation for a diver near the end of a dive would be
a. having middle ear squeeze
b. reverse ear block
c. drysuit squeeze
d. no diiference
b. reverse ear block
happens on ascent - expanded air is trapped inside your ears and cannot be released. exerts pressure, causing ear pain that’s quite similar to the sensation of ear squeeze.
A ruptured ear drum may immediately cause _____ underwater and may also lead to to infection due to water entering the _____
a. vertigo/ middle ear
b. vertigo/ inner ear
a. vertigo/ middle ear
_____ is stomach breathing used before breathold dives in which the lower abdomen expands when you inhale
a. hyperventilation
b. diaphragmatic breathing
c. square breathing
skip breathing
diaphragmatic breathing
After surfacing from a short dive, both buddies complain of headaches, nausea, NARROWED VISION and dizziness. You may suspect they are suffering from
a. decompression sickness
b. nitrogen narcosis
c. hypothermia
d. co poisoning
d. co poisoning
narrowed vision is not a symptom of DCS only CO
shallow water blackout can occur if a breathold diver
a. stays too long underwater
b. ascends too fast
c. doesn’t hyperventilate at the surface
d. doesn’t stay attached to the safety line
a. stays too long underwater
INCORRECT
why does a diver become lightheaded with a drysuit neck seal that is too tight
a. reduces exit of oxygen-poor blood from the brain and lowers blood pressure in the heart, raising the heart rate
b. reduces fresh bloodflow to the brain, raises BP in the head and slows HR
c. squeezes nerves in neck, increased blood flow out of the brain, slows HR
b. reduces fresh bloodflow to the brain, raises BP in the head and slows HR
increased pressure in the brain
cushing syndrome
high BP
low pulse
irregular resps
Smoking, ____ and breath holding during ascent, may contribute to the risk of lung over expansion injury
a. alcohol
b. chest congestion
c. dehydration
d. exercise before the dive
b. chest congestion
INCORRECT
cases of drowning in very cold water can make the revival
a. impossible
b. quite unlikely
c. possible even after fairly long periods of time
d. possible, but only if the patient hasn’t been immersed too long
c. possible even after fairly long periods of time
INCORRECT
you have a surface buoy, dive flag and line. You should also take___ underwater to help with the extra equipment
a. a mesh bag
b. a reel
c. various clips
d. a troch
a reel
INCORRECT
lifting an object. level with object or lift bag
lift bag
INCORRECT
burst disk in a cylinder valve is designed to rupture when the cylinder pressure rises above ___ percent of the cylinder rated pressure. The disk should be replaced
140
regularly
