WAVES
Waves
There are two types of waves mechanical and electromagnetic waves.
Mechanical Waves
Mechanical Waves need medium (or matter) to transfer energy.
A medium is a substance through which a wave can travel.
There are 2 types to mechanical waves, transverse and compressional.
Examples of medium: Air, water, particles, strings, solids, gases and liquids.
Examples of mechanical waves: Sound waves, ocean waves, ripples in water, earthquakes, wave of people at a sporting event.
A medium is a substance through which a wave can travel.
There are 2 types to mechanical waves, transverse and compressional.
Examples of medium: Air, water, particles, strings, solids, gases and liquids.
Examples of mechanical waves: Sound waves, ocean waves, ripples in water, earthquakes, wave of people at a sporting event.
Transverse Waves |
Compressional Waves |
Energy causes the matter in the medium to move up and down or back and forth at right angles to the direction the waves travels.
Crest - The highest point on a wave. Trough - The valley between two waves, its the lowest point. Wavelength - The horizontal distance between the crests or troughs of two consecutive waves. Amplitude - The greatest (peak) value (it can be positive or negative) of a wave. It's the distance from the undisturbed level to the trough or crest. |
Compressional wave is a mechanical wave in which matter in the medium moves forward and backward along the same direction that the waves travels.
Compression - The part of the wave where the particles are crowded together. Rarefaction - The part of the compressional wave where the particles are spread apart. Wavelength - The distance from compression to compression or rarefaction to rarefaction in a compressional wave. |
Electromagnetic Waves
Electromagnetic Waves do not need a medium (matter) to transfer energy but they can go through medium such as air, water and glass.
Electromagnetic waves have similar characteristics as a transverse waves, they have the same parts.
Examples of electromagnetic waves: radiation, TV & radio waves, X-rays, microwaves, lasers, energy from the sun, and visible light.
The electromagnetic spectrum illustrates the range of wavelengths and frequencies of electromagnetic waves.
Electromagnetic waves have similar characteristics as a transverse waves, they have the same parts.
Examples of electromagnetic waves: radiation, TV & radio waves, X-rays, microwaves, lasers, energy from the sun, and visible light.
The electromagnetic spectrum illustrates the range of wavelengths and frequencies of electromagnetic waves.
Larger amplitude = More energy
When a wave is traveling at the same speed, the frequency of a wave increases as the wavelength decreases. The same is true in reverse.
Shorter wavelength = Higher frequency + More energy
Longer wavelength + Lower frequency = Less energy
When a wave is traveling at the same speed, the frequency of a wave increases as the wavelength decreases. The same is true in reverse.
Shorter wavelength = Higher frequency + More energy
Longer wavelength + Lower frequency = Less energy
Sound and Light Waves
Sound waves are compressional mechanical waves that travel through a medium.
Sound waves are compressional because matter in the medium moves back and forth along the same direction that the waves travels. Amplitude and Loudness Loudness is determined by how much energy a sound wave carries. In compressional waves, the amplitude is greater when the particles of the medium are squeezed close together in compression and farther apart in rarefaction. Large amplitude = loud sound because the particles in compression and rarefaction are more spread out. Small amplitude = soft sound because the particles in compression are more compressed and particles in the rarefaction are more spread out. Pitch and Frequency Pitch is how high or low it sounds. Frequency is the number of compressions that pass by a given point in one second. High pitch = high frequency = fast vibrations Low pitch = low frequency = slow vibrations Sound waves with a high pitch have a shorter wavelength. Short wavelength means lots of waves, high frequency and high sound. Long wavelength means fewer waves, low frequency and low sound. Sound energy is described in decibels (dB). |
When light waves strike an object, some of the waves are absorbed by the object, some are reflected and some might pass through it (transmitted).
Absorption is the transfer of light energy to matter. It makes things feel warmer. Reflection occurs when a wave strikes an object or surface and bounces off. Light waves reflecting allows you to see an object. Smooth surfaces allows the reflection to be clear and if it is uneven the image is not clear. Diffraction is the bending of waves around a barrier. |
Changes in Mediums
Waves do not just stop when they reach the end of a medium or obstacle.
Sound behaviors are:
Absorption -
Reflection -
Diffraction -
Refraction -
Sound behaviors are:
Absorption -
Reflection -
Diffraction -
Refraction -