Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. The animations below demonstrate both types of wave and illustrate the difference between the motion of the wave and the motion of the particles in the medium through which the wave is travelling.
If the temperature of the air is said to be at absolute zero, one might conclude that a. the molecules contain a minimum amount of energy. b. the motion of the molecules is at a maximum. c. the molecules are occupying a large volume. the molecules contain a minimum amount of energy.
However, air in the atmosphere will not be perfectly dry since even in very cold air there will still be a trace of water vapor. 2. Another definition of dry air is air that has a low relative humidity. When the relative humidity drops below about 40% the air feels dry to skin. If very low relative humidities persist it can make the skin dry, lips chapped and can put more static in the air. In the winter when air with a low dewpoint from outside is heated and brought inside the air will decrease in relative humidity.