Waves
What Are Waves? A wave is a disturbance that transfers energy from one place to another. Examples Ocean waves Light waves Radio waves Earthquake waves Microwaves
Types of Waves Waves can be classified by what they travel through. Waves that need a medium are called mechanical waves Waves that do not need a medium to travel are called electromagnetic waves
How Waves Move Waves can also be classified by how they move. There are three types Transverse Longitudinal Surface
How Waves Move Continued A transverse wave is a wave in which particles of the medium move in a direction perpendicular to the direction which the wave moves.
How Waves Move Continued A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction which the wave moves.
How Waves Move Continued Surface waves are a combination of transverse and longitudinal waves. Surface waves occur at the surface of two mediums.
Properties of a Transverse Wave Crest- highest part of the wave Trough- Lowest part of the wave Amplitude- Height of the wave Wave length- Distance from crest to crest or from trough to trough
Properties of a Transverse Wave Continued Frequency- number of waves that pass a given point in a certain amount of time Speed- How far a wave travels in one unit of time
Properties of a Longitudinal Wave Compressions- Where the particles of the medium are close together Rarefactions- Where the particles of the medium are far apart Amplitude- of a longitudinal wave is measured by how compressed or rarefied the medium becomes Wave length- Distance from one compression to the next
Properties of a Longitudinal Wave Continued Frequency and speed are the same for both kinds of waves.
Waves And Energy Waves move out in all directions from an energy source The more energy added to a wave the higher its amplitude
Waves and Different Mediums Waves move at different speeds depending on their mediums Waves move faster in solids than in liquids Waves move faster in liquids than in gasses.
Waves and Different Mediums Continued Waves move faster in less dense mediums Waves move faster in warmer mediums
Sound Sound is a disturbance that travels through a medium as a longitudinal wave.
Sound Waves In Different Mediums Sound waves need a medium to travel. The speed of sound changes as it moves from one medium to another.
Sound And The Properties Of Mediums The speed of sound depends on the elasticity, density and temperature of the medium Sound waves move faster in solids than liquids or gasses Sound waves move faster in less dense mediums Sound waves move faster in warmer mediums
The Speed of Sound At normal atmospheric pressure and a temperature of 20 degrees Celsius, a sound wave will travel at approximately 343 m/s; this is approximately equal to 750 miles/hour. 300 000 000 m/s speed of light
Properties Of Sound Intensity- The amount of energy a sound wave carries per second. The more energy put into a wave the larger the amplitude of the wave. Loudness- The perception of the intensity of a sound wave. The greater the intensity the louder the sound.
Properties Of Sound Continued Frequency- The Number of complete sound waves that pass a given point in a certain amount of time. Most people can hear frequency between 20 and 20,000 HZ Ultrasound is sound generated above normal human hearing range. Infrasound is sound generated below normal human hearing range.
Sound waves with high frequency have a high pitch. Sound waves with a low frequency have a low pitch.
Light Electromagnetic waves- Transverse waves that have some electrical properties and some magnetic properties. Electromagnetic waves do not need a medium.
Speed Of Electromagnetic Waves All electromagnetic waves travel at about 3 million meters per second Electromagnetic waves slow down in a medium but still travel a million times faster than sound.
The Electromagnetic Spectrum