Physics Flashcards
(206 cards)
1
Q
What’s the absolute pressure at depth of 254m?
A
26.4 bar
2
Q
What’s the absolute pressure at depth of 254fsw?
A
8.69 ATA
3
Q
A diver is working at 100 fsw for 30 minutes. What volume of gas will he use?
A
151.2 ft3
4
Q
A diver is working at 120 msw for 4 hours. What volume of gas will he use?
A
109.2 m3
5
Q
Two divers are working out of the bell at 75 msw. What volume of gas will they use in 4 hours?
A
142.8 m3
6
Q
An air diver is working at 60 fsw for 20 minutes. What volume of air will he use?
A
70.45 ft3
7
Q
A 64 x 50 litre quad contains gas at a pressure of 100 bar. What is the total volume of gas in the quad?
A
320 m3
8
Q
What volume of gas is available to the diver when the quad pressure falls to 40 bar?
A
192 m3
9
Q
In Question 8, the diver is working at 130 msw. How long can he work for before the quad is changed over?
A
6h 32min
10
Q
A diver is working at 80 msw, breathing from a 16 x 50 litre quad at a pressure of 150 bar. How long could he work for?
A
4h 39min
11
Q
A 64 x 50 litre quad is at a pressure of 205 bar. How much gas is available for use?
A
560 m3
12
Q
A 12 x 50 litre quad is at a pressure of 25 bar. What volume of gas will be needed to fill it to a pressure of 200 bar?
A
105 m3
13
Q
A bail-out bottle has a volume of 12 litres and contains gas at a pressure of 200 bar. What volume of gas is available to him in an emergency at 100 msw?
A
2.15 m3
14
Q
A diver is working at 195 msw, breathing from a 16 x 50 litre quad at a pressure of 110 bar. How long could he work for?
A
1h 18min
15
Q
A bailout bottle has a FV of 6 litres charged to 190 bar. How long it last a diver at depth of 48 msw?
A
4.5min
16
Q
How much gas would a diver consume in 80 min at depth of 42 msw?
A
14.56 m3
17
Q
What’s the apparent weight in seawater of a 1000 m3 pontoon that weighs 1500 tonnes in air?
A
470 tonnes
18
Q
1ft3 of sea water weighs?
A
64.38 lbs
19
Q
What’s the PO2 in breathing air @ 43 msw?
A
1.113 ba
20
Q
What’s the PO2 in breathing air at 97 fsw?
A
0.827 ata
21
Q
What’s the PO2 of 32% nitrox breathed at 27 msw?
A
1.184 ba
22
Q
You require a PO2 of 1.4 ba @ 38 msw, what’s the suitable nitrox mix?
A
28/72
23
Q
What’s the maximum depth a diver could breathe 50/50 mixture with PO2 of 1.4 ba?
A
18 msw
24
Q
What’s the maximum depth for breathing pure O2 when PO2 is 2.8 ba?
A
18 msw
25
At what depth would air equal IMCA wet maximum PPO2?
57 msw
26
If a diver has 1 litre of gas in solution in his body at 1b, how much of the same gas would he have in solution at 50 msw after 10-12h?
6 litres
27
What is the apparent weight in seawater of a 1000 m3 pontoon that weighs 1500 tonnes in air?
470 tonnes
28
A sunken pontoon 10m x 5m x 2m lies on a hard seabed and has an apparent weight of 4 tonnes, you de-ballast a compartment 2m x 2m x1m, what will happen?
It will raise to the surface
29
An object has a density of 168 lbs / ft3 and is 50 feet long, 10 feet high and 8 feet wide. How heavy is it?
300 tonnes
30
If an object 15m long x 4m wide x 3m high had a density of 3800 kg/m3, what would it appear to weigh in fresh water?
504 tonnes
31
If an object 15m long x 4m wide x 3m high floats in seawater with 1m submerged, what must the density be?
343 kg/m3
32
A bell weighs 8 tonnes and displaces 300 ft3 of seawater. How much weight must be added to make it sink?
0.63 tonnes
33
A twin set is filled to 200 bar in a surface temperature of 39°C, underwater it cools to 4°C, what is its new pressure?
177 bar
34
A bailout bottle has a pressure of 2640 psi at 41°F, what was its filling pressure at 70°F?
2793 psi
35
What is the pressure of a bailout bottle at 41°F if its filling pressure was 2793 psi at 70°F?
2640 psi
## Footnote
Calculation uses temperature conversions to find the pressure at 41°F.
36
What will be the new pressure of a quad cooling from 27°C to 17°C if it was initially at 198 bar?
191.4 bar
## Footnote
Involves temperature conversion from Celsius to Kelvin.
37
If a pressurized chamber contains 92 m³ of gas at 68 msw and cools from 31°C to 28°C, what will be the new depth?
67.1 msw
## Footnote
Calculation involves temperature conversion and pressure-volume relationship.
38
What will be the new pressure of an air reservoir with a max working pressure of 200 psi, if it is at 180 psi and the temperature rises from 16°C to 28°C?
187.4 psi
## Footnote
Uses ideal gas law principles for temperature and pressure.
39
What is the upthrust of a pontoon measuring 12m x 7m x 3m with 2.5m submerged in seawater?
216.3 tonnes
## Footnote
Upthrust is calculated using the volume of displaced seawater.
40
What is the weight of a pontoon that floats with an upthrust of 216.3 tonnes?
216.3 tonnes
## Footnote
The weight of a floating object equals the upthrust.
41
How much weight can be placed on a pontoon measuring 12m x 7m x 3m without it sinking?
43.26 tonnes
## Footnote
Calculation involves the buoyant force and the weight of the pontoon.
42
What is the pressure exerted at 1 atmosphere (Sea Level)?
14.7 psi
## Footnote
14.5 psi refers to gauge pressure.
43
Convert 6220 ppm to a percentage.
0.622%
## Footnote
To convert ppm to %, divide by 10,000.
44
What is the absolute pressure exerted at a depth of 165 fsw?
88.2 psi
## Footnote
Absolute pressure is calculated using depth and atmospheric pressure.
45
To convert degrees Celsius to absolute temperature, you must add:
273
## Footnote
This conversion is necessary to change Celsius to Kelvin.
46
What is 32ºC expressed in Fahrenheit?
89.6ºF
## Footnote
Conversion formula: (Celsius x 1.8) + 32.
47
How much gas does a 10 litre flask charged to 200 bar hold?
2000 l
## Footnote
Volume is calculated by multiplying the flask volume by the pressure.
48
Convert 1.000 litres into cubic metres:
1 m³
## Footnote
1000 litres equals 1 cubic metre.
49
How much gas would be required to pressurise a chamber with a floodable volume of 28 m³ to a depth of 37 msw?
103.6 m³
## Footnote
Calculation uses absolute pressure and chamber volume.
50
A diver consumes 1.25 ft³/min at surface. How much gas would he require at a depth of 100 fsw?
5.037 ft³
## Footnote
The calculation involves adjusting consumption based on depth.
51
A compressor has a delivery of 7 ft³/min. To what depth would this support a diver if his consumption is 1.25 ft³/min?
151.8 fsw
## Footnote
Depth calculation considers the ratio of delivery to consumption.
52
A bailout bottle has a FV of 12 litres and is charged to 200 bar. How much gas is available to the diver at a depth of 42 msw?
2241.6 l
## Footnote
Accounts for the working pressure and volume of the bottle.
53
A bank has 45 bottles, each have a FV of 50 litres. How much gas does it contain at a pressure of 185 Bar?
416.25 m³
## Footnote
Total gas calculation uses the number of bottles and their volume.
54
A diver suffering from decompression sickness is to be given a total of 6 cycles of 25 minutes each. The consumption rate is 40 litres per minute at surface. How much gas will be used?
48 m³
## Footnote
Total gas used calculation involves cycles and consumption rate.
55
A DDC with an FV of 25 m³ is pressurised to 80 msw. What was the depth of the DDC when the temperature fell to 30°C?
78.7 msw
## Footnote
Calculation adjusts for temperature changes at given pressure.
56
If you double the pressure on a gas, according to Boyle's law, what will happen to the volume and density?
Volume is halved, Density is doubled
## Footnote
Boyle's law states that pressure and volume are inversely related.
57
What does the reference ± 0.25% marked on a 300 msw gauge refer to in depth?
0.75 msw
## Footnote
This is calculated by multiplying the percentage by the maximum depth.
58
A diver suffering from decompression sickness is given a total of 6 cycles of 25 minutes each. The consumption rate is 0.75 ft³ at surface. How much gas will be used?
453 ft³
## Footnote
Calculation uses depth adjustments for consumption rates.
59
What is the pressure in a chamber at 200 fsw when the temperature is 110°F and cools to 68°F?
179 fsw
## Footnote
Pressure changes with temperature; the specific calculations involve gas laws.
60
How much gas will a liquid absorb at 6 atm if it absorbs 1 cu.ft at sea level?
6 cu.ft
## Footnote
This is based on Henry's law, which states that the amount of gas dissolved is proportional to its partial pressure.
61
Using a 500 msw gauge, what does the reference marked on the gauge ± 0.25% refer in depth?
1.25 msw
## Footnote
The reference depth relates to the precision of the gauge measurement.
62
What is the PO² and PN² in air at 165 fsw assuming air contains 21% oxygen and 79% nitrogen?
1.26 atm and 4.74 atm
## Footnote
These values are derived from the partial pressure calculations based on depth.
63
How much gas is required to pressurise a chamber system with a F.V. of 1400ft³ to a depth of 450 fsw?
19091 ft³
## Footnote
The volume of gas required is calculated considering the depth and chamber volume.
64
What is the gas consumption of 2 divers at a depth of 138fsw for 6 hours 27 mins with a consumption of 1.25 ft³/min?
5011.7 ft³
## Footnote
Total consumption is calculated by multiplying the rate by time.
65
A chamber loses 15m³ of gas per day. How many litres per hour does that relate to?
625 ltrs
## Footnote
Conversion from cubic meters to liters can be achieved by multiplying by 1000 and dividing by 24.
66
What volume of gas is required to pressurise a chamber with a volume of 1200 ft³ to 500 fsw?
18,182 ft³
## Footnote
This is calculated based on the depth and volume of the chamber.
67
After filling a bailout to 3500 psi, what will the pressure be when the temperature drops to 68°F?
3271 psi
## Footnote
The pressure change is calculated using the gas laws relating pressure and temperature.
68
If a balloon has a volume of 5 litres on the surface, what will its volume be at 45 metres?
1 litre
## Footnote
This follows Boyle's law, showing that volume decreases with increased pressure.
69
How much gas is available from a 12 litre bailout bottle at 300 bar and a dive depth of 140 msw?
3324 l
## Footnote
The calculation considers the pressure loss due to depth and regulator pressure.
70
If you pressurise a 25m³ chamber to 75m from a 48 bottle quad, by how much would the quad pressure drop?
78 bar
## Footnote
This involves calculating the volume displacement and pressure drop based on standard conditions.
71
Your company’s PO² during decompression is 500mb. At what depth would the O² % reach 21 %?
14 msw
## Footnote
This is derived from the partial pressure calculations of oxygen in air.
72
What is the total volume of gas in a 64 x 50 litre bottle quad at a pressure of 195 bar?
624 m³
## Footnote
Total volume is calculated by multiplying the number of bottles by their volume and pressure.
73
Convert 5200 PPM to a percentage.
0.52%
## Footnote
Conversion from PPM to percentage involves dividing by 10,000.
74
To convert degrees Fahrenheit to absolute temperature, you must add?
460
## Footnote
This conversion relates to the Rankine scale.
75
What is 65ºF expressed in Celsius?
18.3ºC
## Footnote
The conversion formula from Fahrenheit to Celsius is used here.
76
How much does a 12 litre flask hold when charged to 200 bar?
2.4 m³
## Footnote
Volume calculation is based on pressure and flask volume.
77
Convert 1500 litres into cubic metres.
1.5 m³
## Footnote
The conversion uses the factor of 1000 liters per cubic meter.
78
How much gas would be required to pressurise a chamber with a floodable volume of 20m³ to a depth of 65msw?
130 m³
## Footnote
This is derived from the depth and volume of the chamber.
79
How much gas is available from a bailout bottle at a depth of 75m with a F.V of 12 litres and charged to 300 bar?
3.4 m³
## Footnote
This calculation considers the depth and working pressure.
80
How long would a bailout bottle with a F.V of 10 litres and charged to 200 bar last a diver at a depth of 50 msw?
7.7 mins
## Footnote
Calculated based on the volume available and diver consumption rate.
81
What is the partial pressure of O2 at 35 msw if the breathing gas is air?
945 mb
## Footnote
This is calculated using the formula for partial pressure in a gas mixture.
82
If a diver has a litre of gas in solution in his body at 1 bar(A), how much would he have at 40 msw?
5 ltrs
## Footnote
This is based on the increased pressure at depth affecting gas solubility.
83
What is the reading by gauge of a bell blown down to a depth of 120 msw cooling from 38ºC to 28ºC?
116 msw
## Footnote
The temperature change affects the gas volume and pressure reading.
84
If a bottle reaches a temperature of 42ºC with a start pressure of 200 bar, what would be the pressure after cooling to 25ºC?
189 bar
## Footnote
This is calculated using the gas laws relating pressure and temperature.
85
What is the amount of gas required to blowdown a chamber with a F.V of 25m3 from 80 msw to 110 msw?
75 m³
## Footnote
This calculation considers the change in pressure and volume of the chamber.
86
How much gas would a diver consume over 3 hours at a depth of 75 msw if his consumption was 35 l/min?
53.6 m³
## Footnote
Total consumption is calculated by multiplying the rate by time.
87
Convert 0.28% into PPM.
2800 ppm
## Footnote
Conversion involves multiplying the percentage by 10,000.
88
What is the PP Nitrogen at a depth of 30msw breathing air?
3.2 bar
## Footnote
Calculated based on the depth and nitrogen percentage in air.
89
A compressor has an output of 60m3 per hour at 10 bar outlet pressure. How many divers will it support at a diving depth of 50msw?
4
## Footnote
This is calculated considering the volume of gas required per diver.
90
A diver is working at 80 msw, breathing from 16x50litre quad at a pressure of 150 bar. How long can he work for?
4 hrs 40 mins
## Footnote
Calculated based on the volume available and diver consumption rate.
91
What is the PPO2 at 47msw if the breathing gas is air?
1.2 bar
## Footnote
Derived from the partial pressure of oxygen in air at the given depth.
92
A container measuring 10m x 3m x 4m draws a 2m draft. What is the upthrust received on the seabed?
61.8 te
## Footnote
Upthrust is calculated based on the volume of displaced water.
93
Name the three states of buoyancy.
positive, neutral, negative
## Footnote
These states describe the relationship between an object’s weight and the weight of the fluid it displaces.
94
A pontoon displaces 6m3 of seawater and weighs 5 tons. Is the pontoon positively or negatively buoyant?
1.18 tons positive
## Footnote
Positive buoyancy occurs when the weight of displaced fluid exceeds the object's weight.
95
How much water must be displaced from a lifting bag to initiate a lift for a sealed pipe weighing 8 tons?
1.72 m³
## Footnote
Calculated based on the volume of the cylinder and the weight of the pipe.
96
Is a diving bell that displaces 5m³ of sea water and weighs 4.8t positive buoyant?
Yes
## Footnote
The upthrust exceeds the weight of the bell.
97
Is a diving bell that displaces 180ft³ of sea water and weighs 5.2 imperial tons positive buoyant?
No
## Footnote
The weight of the bell exceeds the upthrust provided by the displaced water.
98
How much force is required to lift a block of concrete 1mx1mx1m lying on the seabed with a density of 2400Kg/m3?
1.37
## Footnote
This involves calculating the buoyant force and the weight of the concrete.
99
What is the weight of 2 imperial tons in pounds?
4480 lbs
100
Is the bell positive buoyant if it weighs 5.2 US tons?
No, the upthrust is 5.17 imperial tons
101
What force is required to lift a block of concrete (1m x 1m x 1m) with a density of 2400kg/m3 clear of the seabed?
1.37 tonnes
102
What is the apparent weight of a welding habitat that weighs 25 tonnes in air and displaces 12m3?
12.64 tonnes
103
How many 1 ton lifting bags are needed to lift a closed length of pipe weighing 12 imperial tons and displacing 140ft3?
8 lifting bags
104
If a chamber is at 345 fsw and the temperature drops to 26°C, what would the depth decrease by?
6.2 fsw
105
How much would the depth decrease if a chamber starts at 145 msw and the temperature drops from 32°C to 28°C?
2 msw
106
What is the absolute pressure on a diver at 30 msw?
4 bar
107
What is the absolute pressure on a diver at 120 fsw?
4.63 Ata
108
What is the absolute depth of a diver at 30 msw?
40m
109
Convert 40ºC to ºF.
104ºF
110
Convert 40ºF to ºC.
4.44ºC
111
Convert 40ºC to ºK.
313ºK
112
Convert 40ºF to ºR.
500ºR
113
What is the gas consumption of a diver working at 140 msw?
525 l/min or 0.525 m3/min
114
What is the gas consumption of a diver working at 120 fsw?
5.79 ft3/min
115
How much gas will a diver working at 15 msw use in 40 minutes?
3.5 m3
116
What is the volume of gas in a 64 x 50 litre quad at a pressure of 200 bar?
640m3
117
How much gas is available for the diver from a 64 x 50 litre quad at 140 msw when changed over at 40 bar?
512m3
118
What is the total volume of gas in a 64 x 50 litre quad at 150 bar?
480 m3
119
How long can a diver work from a 16 x 50 litre quad at 180 bar at a depth of 100 msw before changing over at 40 bar?
4 hours 51 minutes
120
How long can two divers work at 165 msw with a 16 x 50 litre quad at 200 bar before changing over at 40 bar?
1h 44 min
121
How much gas is available for use from a 64 x 50 litre quad at 180 bar down to 30 bar?
480 m3
122
What volume of gas is needed to fill a 16 x 50 litre quad from 40 bar to 200 bar?
128 m3
123
What volume of gas is available for a diver if a quad contains 22,400 ft3 at 3000 psi and is at 2400 psi when changed over at 500 psi?
14,186.7 ft3
124
What is the volume of gas in a quad at 1200 psi if it originally contained 5800 ft3 at 3000 psi?
2320 ft3
125
What is the volume of gas in a quad at 600 psi if it originally contained 21650 ft3 at 2800 psi?
4639 ft3
126
How long can two divers work from a quad containing 22,500 ft at 3000 psi at a depth of 500 fsw before changing over at 500 psi?
6h 58 min
127
How long can a diver work at 280 fsw from a quad at 3000 psi containing 5800 ft3 of gas before changing over at 450 psi?
6h 56 min
128
Is an LP compressor supplying 8 ft3/min at 250 psi suitable for two divers working at 80 fsw?
Not suitable. The divers require 8.56 ft3/min
129
Is an LP compressor supplying 30 ft3/min at 300 psi sufficient for a diver working at 100 fsw?
Suitable. The diver only requires 5.04 ft3/min
130
What is the minimum delivery volume and pressure required for two divers working at 75 fsw using an LP compressor?
Minimum delivery 8.18 ft3/min, minimum pressure 195.1 psi
131
How long would a 12 litre bail out bottle at 180 bar last a diver at 180 msw in an emergency?
2.38 minutes or 2 minutes 23 seconds
132
How much time does a diver have if a bail out bottle with a floodable volume of 12 litres is filled to 200 bar and the surface supply fails at 120 msw?
4.08 minutes or 4 minutes 5 seconds
133
How long does a diver have to return to the bell if a bail out cylinder contains 100 ft3 of gas at 3500 psi, but is at 3000 psi when the surface supply fails at 450 fsw?
3.43 minutes or 3 minutes 26 seconds
134
What will be the pressure in a bail out cylinder if the temperature drops from 30°C to 4°C after filling to 200 bar?
182.8 bar
135
What will be the pressure in a bail out cylinder if the temperature drops from 90°F to 40°F after filling to 3000 psi?
2727.3 psi
136
What will be the pressure in a bail out bottle if the temperature drops from 35°C to 12°C after filling to 200 bar?
185 bar
137
What will be the pressure in a bail out bottle if the temperature drops from 75°F to 38°F after filling to 3500 psi?
3258 psi
138
What will the pressure in a quad filled to 200 bar at 20°C be when the temperature rises to 40°C?
214 bar
139
How much nitrogen can body tissue absorb at a PPN2 of 1.4 ATA if it can absorb 0.27 litres at 0.79 ATA?
0.491 litres
140
What is the PPN2 for a diver breathing air at 50 msw?
4.74 bar
141
What is the PP02 in a 12% mix at 150 fsw?
0.665 at
142
What is the PP02 in a chamber at 60 fsw with 21% oxygen?
0.592 at
143
What are the PP02 and PPN2 at 150 fsw in air?
* PP02: 1.16 at
* PPN2: 4.38 at
144
What is the PP02 and PPN2 for a 40% nitrox mix at 20 msw?
* PP02: 1.2 bar
* PPN2: 1.8 bar
145
What is the EAD for a 40% nitrox mix at 110 fsw, and why can't this mix be used at that depth?
* EAD: 75.6 fsw
* Reason: PP02 is 1.73 bar, exceeding the recommended maximum of 1.4 bar
146
What volume of gas is needed to pressurise a 45m3 chamber system to 130 msw?
585 m3
147
What volume of gas is required to pressurise a 1500ft3 chamber system to 500 fsw?
22727 ft3
148
What volume of gas is required to pressurise a 35m3 chamber system to 120 msw?
420 m3
149
What volume of gas is needed to pressurise a 38m3 chamber system to 195 msw?
741 m3
150
What volume of gas is required to pressurise an 875 ft3 chamber system to 400 fsw?
10606 ft3
151
If a chamber is at 400 fsw and the temperature decreases from 81°F to 82°F, what would the depth change to?
399 fsw
152
If a chamber is at a depth of 120 msw and the temperature drops from 33°C to 30°C without adding gas, what would the depth change be?
1.27 msw
153
By how much would the depth decrease if a chamber at 160 msw and 29°C starts at 32°C without adding gas?
1.67 msw
154
What would the depth decrease to if a chamber at 345 fsw and 86°F drops to 76°F without adding gas?
338.1 fsw
155
Is a diving bell that displaces 5.5 m3 of sea water and weighs 4.75 tonnes positively buoyant?
Positively buoyant by 0.915 tonnes
156
Is a diving bell that displaces 200 ft3 of sea water and weighs 5.8 imperial tons positively buoyant?
Negatively buoyant by 0.05 tons
157
Is a diving bell that displaces 6m3 of sea water and weighs 6.1 tonnes positively buoyant?
Positively buoyant by 0.08 tonnes
158
Would the diving bell that displaces 6m3 of sea water and weighs 6.1 tonnes be positively buoyant in fresh water?
Negatively buoyant by 0.01 tons
159
Is a diving bell that displaces 180 ft of sea water and weighs 5.2 imperial tons positively buoyant?
Negatively buoyant by 0.03 tons
160
What is the weight of a bell that is negatively buoyant by 0.01 tons?
6.10 - 6.00 tons
161
How is the buoyancy of a diving bell determined when it displaces 180 ft of sea water and weighs 5.2 imperial tons?
Negatively buoyant by (5.20 - 5.17) tons = 0.03 tons
162
What is the buoyancy of a diving bell that weighs 5.2 US tons and displaces 180 ft3 of sea water?
Positively buoyant by (5.79 - 5.20) tonnes = 0.59 ton
163
What is the weight of a steel pontoon measuring 5m x 3m x 3m that is floating with 2m submerged in fresh water?
30 tonnes
164
How much weight can be added to a pontoon before it sinks if it weighs 30 tonnes?
15 tonnes
165
What is the weight of a concrete block measuring 1.0m by 1.2m by 1.5m in air?
32 tonnes
166
What is the weight of the same concrete block when submerged in water?
46 tonnes
167
How much force is required to lift a 1m x 1m x 1m concrete block clear of the seabed?
1.37 tonnes
168
What does a welding habitat weighing 28 tonnes in air weigh in sea water after displacing 14m3?
13.58 tonnes
169
How many 1 ton lifting bags are needed to lift a closed length of pipe weighing 14 imperial tons that displaces 140 ft3?
10 bags
170
What volume of fresh water does a blind flange made of 1 inch steel plate and 30cm in diameter displace?
1.796 litres
171
What is the weight in air of a flooded spoolpiece with an outside diameter of 30 cm, wall thickness of 3 cm, and length of 12 metres?
2409.5 kg
172
What is the weight in seawater of the same flooded spoolpiece?
2095.35 kg
173
What is the approximate weight in seawater of a concrete DMA that weighs 1 tonne in air?
0.57 tonnes
174
What is the absolute pressure at a depth of 254 msw?
26.4 bar
175
What is the absolute pressure at a depth of 254 fsw?
8.69 ata
176
What volume of gas will a diver use working at 120 msw for 4 hours?
109.2 m3
177
What volume of gas will a diver use working at 100 fsw for 30 minutes?
151.2 ft3
178
What volume of gas will two divers use working out of the bell at 75 msw for 4 hours?
142.8 m3
179
What is the total volume of gas in a 64 x 50 litre quad at a pressure of 100 bar?
320 m3
180
How long can a diver work at 130 msw before changing over the quad when the pressure drops to 40 bar?
6 hours 32 minutes
181
How much gas is available in a bail-out bottle with a volume of 12 litres at 200 bar when the diver is at 100 msw?
2.15 m3
182
What is the weight in seawater of a welding habitat that weighs 25 tonnes in air and displaces 12 m3?
12.64 tonnes
183
What pressure is a bail-out bottle at when filled to 200 bar at a temperature of 30°C and then drops to 4°C?
183 bar gauge
184
What is the volume of gas available to a diver if a quad contains 22,500 ft3 at a pressure of 3000 psi and can be used until 450 psi?
19125 ft3
185
What is the density of concrete used in the calculations for underwater lifting?
2400 kg/m3
186
What is the weight of a flooded spoolpiece with a 16 inch outside diameter and a wall thickness of 1 inch at a pressure of 3000 psi?
4.725,69 lbs
187
How much gas will be needed to fill a 12 x 50 litre quad to a pressure of 200 bar from 25 bar?
105 m3
188
What is the volume of gas available in a chamber system with a volume of 40 m3 pressurized to 150 msw?
600 m3
189
What is the volume of gas required to pressurize a chamber system with a volume of 1200 ft3 to 500 fsw?
18180 ft3
190
What is the gas consumption of the diver?
64 x 1.25 ft3
## Footnote
The diver has a gas consumption rate of 5.8 ft/min.
191
What volume of gas is available for the diver when the quad is changed over at 40 bar?
512m3
## Footnote
A 64 x 50 litre quad holds gas at a pressure of 200 bar.
192
How long can the diver work if the quad holds gas at 180 bar and is changed over at 40 bar?
4 hours 51 minutes
## Footnote
The quad size is 16 x 50 litres and the diver is working at 100 msw.
193
Is the lightweight LP compressor supplying 8ft/min at 250 psi suitable for two divers at 80 fsw?
27 psi: suitable
8. 56ft/min: not sufficient
194
Is the lightweight LP compressor supplying 120 l/min at 15 bar suitable for a diver working at 20 msw?
The supply pressure is 15 bar, which is suitable.
## Footnote
The compressor supplies 120 L/min, sufficient for the dive.
195
How long would a 12-litre bail out bottle at 180 bar last a diver working at 180 msw in an emergency?
2 min 23 sec
## Footnote
Limits umbilical length to 23 metres from the bell.
196
What volume of gas is needed to pressurise a 45 m3 chamber system to 130 msw?
585m3
197
What is the absolute pressure on a diver at 120 fsw?
4.63 ATA
## Footnote
Gauge pressure is 3.63 ATA.
198
Convert 126 fsw into msw.
38.4 msw
## Footnote
98 msw converts to 321.44 fsw.
199
Convert 196 bar into PSI.
2842 psi
## Footnote
155 psi converts to 10.68 bar.
200
Convert 28 C into degrees F.
82.4 F
## Footnote
50 F converts to 10 C.
201
Convert 368 fsw into ATA.
12.15 ATA
202
Convert 49 m2 into ft2.
527.24 ft2
## Footnote
Ratio of 10.76.
203
Convert 98 litres into cu ft.
3.46 cu ft
## Footnote
5.7 cu ft converts to 161.42 litres.
204
How many cubic feet are in a cubic meter?
35.32 cubic feet
205
How many litres are in a cubic foot?
28.32 litres
206
How much extra buoyancy is needed for a wet bell to make it 500 lbs positive?
1205 lbs
## Footnote
The wet bell weighs 7.5 tons and receives an upthrust of 16,095 lbs.
