Terms:

-         Crests

o       A 'crest' is the point on a wave with the maximum value or upward displacement within a cycle

-         Troughs

o       A trough is the opposite of a crest, so the minimum or lowest point in a cycle

-         longitudinal waves

o       In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. The particles do not move down the tube with the wave; they simply oscillate back and forth about their individual equilibrium positions.

-         transverse waves

o       In a transverse wave the particle displacement is perpendicular to the direction of wave propagation. The particles do not move along with the wave; they simply oscillate up and down about their individual equilibrium positions as the wave passes by.

-         Reflection

o       change in wave direction after it strikes a reflective surface, causing the angle the wave makes with the reflective surface in relation to a normal line to the surface to equal the angle the reflected wave makes with the same normal line

-         refraction

o       change in wave direction because of a change in the wave's speed from entering a new medium.

Introduction to waves