Question

structure and composition of the atmosphere
quiz complete
5
which phrase describes air density?
increases as altitude increases
equals mass divided by volume
pushes molecules in one direction
exerts less pressure as it increases

Explanation:

To determine the phrase describing air density, recall the definition of density: density ($
ho$) is defined as mass ($m$) divided by volume ($V$), i.e., $
ho=\frac{m}{V}$. Let's analyze each option:

• "increases as altitude increases": Air density decreases with increasing altitude, so this is incorrect.
• "equals mass divided by volume": This matches the definition of density, so this is correct.
• "pushes molecules in one direction": This describes pressure or force, not density.
• "exerts less pressure as it increases": This describes air pressure with altitude, not density.

Answer:

equals mass divided by volume