Characteristics:
Mediums Types of Mediums Vibrations
TEKS Objectives •
The student knows the effects of waves on everyday life. The student is expected to demonstrate wave types and their characteristics through a variety of activities such as modeling with ropes and coils, activating tuning forks, and interpreting data on seismic waves; demonstrate wave interactions including interference, polarization, reflection, refraction, and resonance within various materials.
Additional resources • Skip to information
A wave is a disturbance that transmits energy and can do work, whether a ripple in a pool or the movement of sound. There are a variety of waves, ranging from light to a tsunami on the coast of a Japanese town. As a wave moves away from its source, it loses energy because the net energy of the wavefront remains the same, but the area over which the energy is spread increases.
To see these forms of waves in an animation, please visit this page concerning wave visualizations. Be sure that you have the most recent Macromedia Flash ® and Shockwave plugins installed!
A medium is the matter that a wave travels through. Most waves travel through mediums. Waves that require a medium are called mechanical waves.
Light, however, does not require a medium. Light wavs consist of changing electric and magnetic fields - light waves, are therefore called electromagnetic waves.
A wave that does not travel through a medium can travel through a process called "vacuum".
Mediums can be classified under the following names concerning their physical properties.
Vibrations cause waves, whether in the form of charged particles or vibrating objects. Every particle in the medium or the charged particle has potential energy which cuases it to move past the resting position and gain more potential energy. This is called simple harmonic motion.
Since the particles contact each other, the energy of the first particle is dampened while the second particle receives energy causing damped harmonic motion.
Telephones • "The Physics Classroom" • Visit this site
Telephone chord waves provide another mental picture of waves. A telephone chord wave is created when a contented teenager stretches out the chord and unconsciously vibrates one end of the chord. A disturbance is created which subsequently moves along the chord, reaches the wall and returns to the hand set. A single disturbance can be created by the single vibration of one end of the chord or a repeated disturbance can be created by the repeated and regular vibration of the end of the chord. If one ever consciously awakes and observes the motion of the telephone chord, they soon become aware of a wealth of physics. The shape of the chord is actually influenced by the frequency at which it is vibrated. If the student vibrates the chord rather frequently, then a short wave is created; and if the student vibrates the chord at a low frequency (not so often), then a long wave is created.
