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.
Density of (Gas) In commercial applications where air is the gas, its density is at 70Âº Fahrenheit and 29.92 inches of mercury (barometric pressure), and the. airflow is not compressed (under 10 IN w.c.), the formula reduces to: Air Velocity (FPM) = 4005 x Velocity Pressure (IN w.c.)