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.
Liquids boil at the temperature at which the vapor pressure is equal to the pressure on the liquid from its surroundings. Raising the pressure on a gas therefore effectively increases the boiling point of the liquid. Suppose that we have water vapor (or steam) in a closed container at 120 o C and 1 atm.iquids boil at the temperature at which the vapor pressure is equal to the pressure on the liquid from its surroundings. Raising the pressure on a gas therefore effectively increases the boiling point of the liquid. Suppose that we have water vapor (or steam) in a closed container at 120 o C and 1 atm.