Torrentz will always love you. The concept the world of physics by john avison pdf free download also be applied to periodic waves of non-sinusoidal shape. Water waves are variations in the height of a body of water.
Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in sinusoidal waves over deep water a particle near the water’s surface moves in a circle of the same diameter as the wave height, unrelated to wavelength. Note that the wavelengths in audible sound are much longer than those in visible light. Sinusoidal standing waves in a box that constrains the end points to be nodes will have an integer number of half wavelengths fitting in the box. The upper figure shows three standing waves in a box. For example, for an electromagnetic wave, if the box has ideal metal walls, the condition for nodes at the walls results because the metal walls cannot support a tangential electric field, forcing the wave to have zero amplitude at the wall.
The stationary wave can be viewed as the sum of two traveling sinusoidal waves of oppositely directed velocities. Consequently, wavelength, period, and wave velocity are related just as for a traveling wave. The first form, using reciprocal wavelength in the phase, does not generalize as easily to a wave in an arbitrary direction. Wavelength is decreased in a medium with slower propagation. Refraction: upon entering a medium where its speed is lower, the wave changes direction. The speed of a wave depends upon the medium in which it propagates. The wave velocity in one medium not only may differ from that in another, but the velocity typically varies with wavelength.