wave interactions
standing wave
is a wave that appears to stand in one place even though it is two waves interfering as they pass through each other.
Resonance
is an increase in the amplitude of a vibration that occurs when external vibrations match an object's natural frequency.
reflection
is used in everyday life to describe what we see in a in the mirror or on the surface of the water. In physics, a reflection is when a wave encounters a new medium that acts as a barrier, causing the wave to return to the original medium. The wave "reflects" off the barrier at an angle that is incident to the angle of the wave hitting the barrier.
wave interference
may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. How amplitude is affected depends on the type of interference. Interference can be constructive or destructive.
Absorption
occurs when a wave comes into contact with a medium and causes the medium's molecules to vibrate and move. This vibration absorbs or takes some of the energy away from the wave and less of the energy is reflected.
Diffraction
occurs when a wave stays in the same medium but bends around an obstacle. This can occur when the wave encounters a small object in its path or when the wave is forced through a small opening.
refraction
of a wave occurs when a wave changes direction upon moving from one medium to another. Along with the change of direction, refraction also causes a change in the wave length and the speed of the wave. The amount of change in the wave due to refraction is dependent on the refractive index of the mediums.
examples of absorption
Example: When ocean waves reach a shoreline, most of their energy is absorbed by the shore. Another example of absorption is black pavement which absorbs energy from light. The black pavement becomes hot from absorbing the light waves and little of the light is reflected making the pavement appear black. A white strip painted on the pavement will reflect more of the light and absorb less. As a result, the white stripe will be less hot.
Examples of diffraction
For example, sound waves bend around corners much more than light does. That's why you can hear but not see around corners. Another example of diffraction is when a water wave hits a boat and bends around the boat. The waves after the boat are changed or diffracted. For a given type of wave, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength .
examples of refraction
One example of refraction is a prism. When white light enters the prism, the different wavelengths of light are each refracted differently, and the light is split into a spectrum of colors. Light bends as it passes from air to water .The bending of the light causes a pencil placed in water to appear broken. Waves strike a wall at an angle, called the angle of indiance. The waves are reflected at the same angle, called the angle of reflection, but in a different direction. Both angles are measured relative to a line that is perpendicular to the wall.
destructive interference
When the crests of one wave collide with the trough of another wave, one amplitude subtracts from the other. This principle is known as
constructive interference
When the crests or troughs of two interfering waves of similar sizes collide and form a wave with an amplitude greater than either of the original waves. This principle is known as
examples of reflection
an echo, the reflection of ocean waves off a rocky coast, light from a light source, such as the sun or a light bub, shining on the object and some of the light is reflected.