Strep throat Strep throat is a throat infection causing symptoms including a red sore throat with white patches. Hay fever Hay fever, an allergic reaction to outdoor pollens and molds, causes nasal congestion, itchy eyes, and more.
Air Density is the mass per unit volume of the air. For example, the standard air density at sea level is 1.225 kg/m 3 (0.076474 pounds/ft 3). Relative Density is the ratio of the actual air density to the standard sea level density, expressed as a percentage.
This is because a higher-than-normal temperature (a warm, balmy day) tends to be accompanied by a higher-than-normal barometric pressure of the atmosphere. That is, high temperature tends to decrease air density, while high pressure tends to increase air density. The air density ratio column in Table 3.1-1, which is the ratio of standard air density at altitude to the standard air density at sea level, shows that the air density decreases rapidly as altitude increases.