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.
The answer is because temperature sets a limit to how much water vapor can be in the air. Even in tropical air, once the volume of water vapor in the atmosphere approaches 4% it will begin to condense out of the air (rain). The condensing of water vapor prevents the percentage of water vapor in the air from increasing. If temperatures were much warmer, there would be a potential to have more than 4% water vapor in the atmosphere. Think about the steam trapped in a tea kettle.