A mule is a cross between a donkey and a horse. Therefore, a mule will have some donkey characteristics such as large ears, a head just a bit too large for its body, a skimpie â¦ r tail, some still have the cross on their backs from the donkey, and they often have small looking feet.
Density of air. The density of air, Ï (Greek: rho) (air density), is the mass per unit volume of Earth's atmosphere, and is a useful value in aeronautics and other sciences. Air density decreases with increasing altitude, as does air pressure. It also changes with variances in temperature or humidity.
The formal definition of density altitude is certainly correct, but the important thing to understand is that density altitude is an indicator of aircraft performance. The term comes from the fact that the density of the air decreases with altitude. A âhighâ density altitude means that air density is reduced, which has an adverse impact on aircraft performance. The published performance criteria in the Pilotâs Operating Handbook (POH) are generally based on