Diving Physics

Question 1

What are the five types of pressure

Answer 1

Absolute pressure
Ambient pressure
Gauge pressure
Atmospheric pressure
Hydrostatic pressure

Question 2

Absolute pressure

Answer 2

depth (m)/10 + 1atm

Every 10m there is one additional atmosphere of pressure

Question 3

Ambient pressure

Answer 3

same as absolute pressure (pressure surrounding a diver)

Question 4

Gauge pressure

Answer 4

Ignore additional atmosphere
Read 0 at surface instead of 1
Read depth as pressure

Question 5

Combined gas law

Answer 5

(P1 x V1)/T1 = (P2 x V2)/T2

Question 6

Boyle’s Law

Answer 6

For gas at a constant temp, the volume will vary dependent on the pressure of the gas
More pressure = compress
Less pressure = expand

P1 x V1 = P2 x V2

Question 7

Absolute temperature

Answer 7

Kelvin = degrees C + 273

Question 8

Charles’ Law

Answer 8

Volume of gas will vary with absolute temperature
V1/T1 = V2/T2

Pressure of gas will vary with absolute temperature
P1/T1 = P2/T2

Question 9

How do lift bags maintain a constant volume

Answer 9

Vent air as they surface
Relief valves similar to a BCD

Question 10

How many L lift bag is required for a 100kg object

Answer 10

100L - 1L of displacement will lift 1kg in fresh water

Question 11

Buoyancy calculations

Answer 11

apparent weight = actual weight - upthrust
upthrust = displacement
apparent weight = actual weight - (displacement x density of salt water)