Waves

Waves A wave is a disturbance that transfers energy from place to place. Energy is defined as the ability to do work.

What Causes Waves? Waves are created when a source of energy causes a medium to vibrate. A moving object has energy. The moving object can transfer energy to a nearby medium, creating a wave.

What are some sources Wind- waves on water

What are some sources Boat propeller

What are some sources Earthquake- Seismic Wave

What are some sources Jet brakes the sound barrier

What are some sources Sun’s Nuclear Fusion- Electromagnetic waves

Types of Waves There are two main types of waves Mechanical waves Electromagnetic waves

Mechanical Waves These waves require something to travel through. The material through which a wave travels is called a medium. Waves that require a medium through which to travel are called Mechanical Waves.

Electromagnetic Waves These waves can travel through empty space or through matter. These form when charged particles vibrate. Many of these waves come to us from space such as the energy from the sun. Once the wave reaches earth, it can travel through matter as well.

Speed of Mechanical Waves

This means they travel at 300, 000, 000 m/s Speed of EM Waves This means they travel at 300, 000, 000 m/s

Although waves travel through a medium, they do not carry the medium itself with them.

The medium itself goes nowhere The medium itself goes nowhere.  The individual atoms and molecules in the medium oscillate about their equilibrium position, but their average position does not change.  As they interact with their neighbors, they transfer some of their energy to them.  The neighboring atoms in turn transfer this energy to their neighbors down the line.  In this way the energy is transported throughout the medium, without the transport of any matter.

Types of wave Movement Transverse waves Longitudinal waves Surface Waves

Transverse Waves If the displacement of the individual atoms or molecules is perpendicular to the direction the wave is traveling, the wave is called a transverse wave.

Longitudinal Waves In a longitudinal wave the particle displacement is parallel to the direction of wave propagation

Surface Waves Surface waves are combinations of transverse and longitudinal waves. These waves occur at the surface of two mediums, water and air Earth and air

Water Waves Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the water, the particles travel in clockwise circles.

Surface Waves

Rayleigh surface waves Another example of waves with both longitudinal and transverse motion may be found in solids as Rayleigh surface waves. The particles in a solid, through which a wave passes, trace out a clockwise ellipse

Properties of waves Amplitude Wavelength Frequency Speed The maximum distance the particles of the medium carrying the wave move away from rest positions. Wavelength The distance between two corresponding parts of a wave. Frequency The number of complete waves that pass a given point in a certain amount of time. Speed Speed=Wavelength x frequency

Wavelength of Transverse Waves

Wavelength of Mechanical Waves

Amplitude of Transverse Waves

Amplitude of Longitudinal Waves

Frequency of Transverse Waves

Frequency of Mechanical Waves Wave A has less frequency than Wave B

Waves Transfers energy Often travels through a medium (Gas, liquid, solid) Medium is NOT carried along Created when energy causes a vibration Wind- Waves on water Boat propeller Earthquake-Seismic Wave Jet brakes sound barrier Sun’s Nuclear Fusion- electromagnetic waves

Waves move at right angles Longitudinal Waves Types of Waves Transverse Waves Waves move at right angles Longitudinal Waves Push Pull Waves Surface Waves Transverse AND Longitudinal