Objective of this demonstration is to kinesthetically learn about the motions of waves and the mediums through which they travel.
Standards: Position and Motion of Objects (object position and motion change; sound production by vibration), Motions and Forces (inertia with moving objects), and Interactions of Energy and Matter (waves possessing energy and transferring it through interaction with matter).
Materials: Eager students
(1) Ask for approximately ten student volunteers to form a straight line facing the class in which they position themselves shoulder to shoulder. Ensure that the students are just touching shoulders and not bracing or supporting themselves against the other students.
(2) Stand at one end of the line and gently push through the student’s shoulder toward the opposite end of the line.
(3) Instruct the class to make observations and repeat if desired.
(4) Tell the volunteers to interlock their arms with each other.
(5) Begin pulling and pushing the first student back and forth in a rocking motion until the entire line of students is moving.
(6) Instruct the class to make observations and repeat if desired.
Science Behind It: The first demonstration represents a longitudinal or compression wave while the second demonstration represents a transverse wave. Make the students aware that waves are energy moving through a medium whether it be water, the earth, or in this case the students. Longitudinal waves vibrate parallel to or in the same direction as their medium. In contrast, transverse waves travel in a perpendicular direction to that of their medium. Also inform the class that the medium itself does not have to nor generally does not move. Other objects such as ropes or slinkies will essentially produce the same effect as this demonstration.