Nate Core Practice Test

What happens to air velocity as humidity increases?

1. It increases

2. It decreases

3. It remains the same

4. It fluctuates randomly

The correct answer is: It decreases

As humidity increases, the air velocity tends to decrease. This phenomenon occurs due to the physical properties of water vapor, which is lighter than the nitrogen and oxygen that predominantly make up the atmosphere. When humidity rises, the air becomes less dense because water vapor replaces some of the heavier nitrogen and oxygen molecules. As a result, the buoyancy of the air is affected, leading to a decrease in air movement or velocity. Additionally, higher humidity can lead to more stable atmospheric conditions, which means that the driving forces behind air movement, such as temperature differentials and pressure gradients, may be less pronounced. This stability further contributes to the reduction in air velocity. Thus, as humidity increases, the density and stability of the air contribute to a decrease in air velocity, confirming that the correct answer is indeed that it decreases.