Waves along a line of students
Introduce transverse and longitudinal waves with a kinaesthetic experience. This can help students to understand and remember what each of these wave types are.
Apparatus and materials
Health & Safety and Technical notes
Students stand side to side and link arms in a line. Send gentle transverse waves and pulses down the line.
For longitudinal waves and pulses, students all turn right (or left) and place their hands on the shoulders of the student in front, with elbows kept bent.
1 To carry out these experiments successfully, you will need class discipline almost at the military parade ground level. They do illustrate clearly, however, the motion of particles in a medium that constitutes a passing wave.
2 With students in the second arrangement, you could ask the students to imagine what happens when a medium is strained beyond its elastic limit.
3 From the rear of the line, imagine that the end student is given a good shove to send a strong pulse down the line. Think what would happen next. When the students have figuratively 'picked themselves up', discuss the difference between this pulse and all the others so far: that the particles did not, in this case, return to their original places.
4 Another way to model transverse waves is using a wave machine (cheap and simple to construct), as this video from the National STEM Centre eLibrary shows.
This experiment was safety-checked in February 2006