Question

State two factors that affect the atmospheric pressure as we go up.

Answer 1

Variation of atmospheric pressure with altitude:-

1. The atmosphere may be considered to consist of a number of parallel layers of air. The pressure on any layer is equal to the thrust of the air column above it.
2. The thickness of the air column above any point decreases with altitude. As a result, the atmospheric pressure also decreases as we go to a higher altitude.
3. The density of air near the earth's surface is higher and decreases with the altitude above the surface of the earth.
4. The decrease in the density of air is rapid at lower altitudes and becomes slow at higher altitudes. Thus the atmospheric pressure also decreases with altitude.

The decrease in atmospheric pressure with altitude depends upon the following two factors:

1. Decrease in the thickness of the air column. This produces a linear decrease in the atmospheric pressure with altitude.
2. Decrease in the density of air with altitude. This slows down the decrease in atmospheric pressure with altitude.