Test: PADI Open Water Chapter One Quiz
Description: Questions from the PADI Open Water Diver Manual
Pressure changes in water for a given ascent or descent are much more substantial than the same distance ascent or descent in air because water weighs more.
When you exhale, your lung volume decreases. This means you have _____ buoyancy.
The three major air spaces affected by pressure when you descend are:
sinuses, lungs stomach
mask, ears and sinuses
lungs, mask and ears
If a sealed, flexible bag of air is taken from the water surface to a depth of 30m/99ft, what is the Pressure on the bag, the Volume relative the the volume at the surface and the density o the air relative to the density at the surface
Depth Pressure Volume Density 0m/oft 1 bar/ata x 1 x 1 10m/33ft 2 bar/ata 1/2 x 2 20m/66ft 3 bar/ata 1/3 x 3 30m/99ft 4 bar/ata 1/4 x 4 40m/132ft 5 bar/ata 1/5 x 5
5 bar/ata, 1/5, X5
3 bar/ata, 1/3, X3
4 bar/ata, 1/4, X4
2 bar/ata, 1/2, X2
Buoyancy control is one of the most important skills you can master because it allows you to control where you are in the water
An object will be more buoyant in _____ than it will be in _____.
fresh water, salt water
salt water, fresh water
A squeeze is:
a pressure imbalance in which pressure inside an air space exceeds pressure outside an air space, resulting in pain or discomfort
a pressure imbalance in which pressure outside an air space exceeds pressure inside an air space, resulting in pain or discomfort
What two pieces of equipment do you use to control your buoyancy?
lead weight, BCD
You usually only feel pressure in body air spaces because:
Your body is mostly made of incompressable liquid, but air is compressible and changes volume with pressure changes.
Water is denser than air, which resists pressure better
An object is positively buoyant when:
It displaces a volume of water weighing less than its own weight
It displaces a volume of water weighing more than its own weight
It displaces a volume of water weighing equal to its own weight
Equalization is adding air to an air space as you descend so the pressure in an air space equals the surrounding water pressure.