A wave is traveling through a medium. As it travels, it displaces particles of matter in the same direction as the wave is trave
ling. This type of wave is a longitudinal wave because the particles move parallel to the direction that the wave is traveling.
transverse wave because of the way the particles are displaced as the wave passes through.
longitudinal wave because it moves forward through a medium causing the particles to vibrate.
transverse wave because it is not traveling in a vacuum and the particles are moving.
Making the lumber thick will make it stiff, which seems good. On the other hand, with thicker lumber, differences in expansion on the two faces have more leverage to make the lumber move.
