Wave Motion - Mission WM1 Detailed Help


The diagrams below depict various wave patterns in a slinky. The arrows represent potential direction of hand movements for the creation of such patterns. Which diagram - A, B, C, or D - represents the appropriate hand movements and patterns for a longitudinal wave?


 
A wave is introduced into a slinky by vibrating or wiggling one or more coils. The arrows in the diagram represent the direction that the hand is vibrating or wiggling in order to introduce the disturbance at the first coil. The subsequent appearance of the slinky as the result of the periodic and repeating disturbance of the first coil is shown by the arrangement of the other coils.


 
Definition of Longitudinal Waves and Transverse Waves:
There are a variety of wave types that can exist in a medium. The two most common types are longitudinal and transverse.

transverse wave is a type of wave in which particles of the medium vibrate in a direction that is perpendicular to the direction that the wave moves.

longitudinal wave is a type of wave in which particles of the medium vibrate in a direction that is parallel to the direction that the wave moves.


 
If you have a slinky, then you can try this at home. Have a friend hold one end of a slinky as you hold the other. Spread apart so that the slinky stretches out between you. Have your friend hold his/her end steady as you try to create a longitudinal wave that moves from your end to the other end. Remember, you want a longitudinal wave - so the coils must vibrate back and forth towards your friend and back towards yourself. Which way do you have to shake the first coil to create this longitudinal wave?
 
If you wish to create a longitudinal wave that moves from your end to your friend's end, then you must vibrate your end in such a manner that all the coils within the slinky begin to vibrate in the direction of your friend and then back towards you. To do this, you must push the first coil towards your friend and then quickly pull it back towards yourself. Repeating this vibrating process over and over creates a longitudinal wave.