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.
Any given volume of air has density. The density of air can vary from place to place and from time to time. The difference in barometric pressure between observation sites at different elevations is a measure of the density of air in a column of air between those two elevations. Cold air is denser than warm air.