Longitudinal Waves. To see a animations of spherical longitudinal waves check out: In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. The animation at right shows a one-dimensional longitudinal plane wave propagating down a tube.
The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
Take away ideas and understandings. 1  Water vapor pressure increases with temperature. 2  Definitions of evaporation, evapotranspiration, condensation, and precipitation and how these processes relate to saturation water vapor pressure curve. 3  The presence of condensation nuclei are critical for the formation of clouds.