The Density of Air
Density refers to a substance's mass per unit of volume. In the United States "pounds per cubic feet" is used to measure density.
The density of air depends largely on altitude and temperature, but for the purposes of this lesson we are mainly concerned with its density at sea level. And at sea level, the density of air is 0.08 lbs/ft³.
Air can be compressed by applying additional pressure, and this increases its density. For example, the density of the air in a full scuba cylinder is much higher than in an empty one. And as you'll learn later in this chapter, air density increases as you descend in the water, and decreases as you ascend.
The density of air depends largely on altitude and temperature, but for the purposes of this lesson we are mainly concerned with its density at sea level. And at sea level, the density of air is 0.08 lbs/ft³.
Air can be compressed by applying additional pressure, and this increases its density. For example, the density of the air in a full scuba cylinder is much higher than in an empty one. And as you'll learn later in this chapter, air density increases as you descend in the water, and decreases as you ascend.
