# Two Main Wave Types

## Overview

• Waves are disturbances that transfer energy from one point to another in various forms.
• There are two main types of waves: Mechanical waves and Electromagnetic waves.

## Mechanical Waves

• Mechanical waves require a medium (solid, liquid, or gas) through which to travel.
• These waves are created when a source of energy causes a vibration to travel through the medium.
• Two types of mechanical waves exist: Longitudinal waves and Transverse waves.

## Longitudinal Waves

• In longitudinal waves, particles in the medium oscillate back and forth along the direction of wave propagation.
• Sound waves are a common example of longitudinal waves.
• In these waves, areas where particles are close together are known as compressions, while areas where particles are spread out are known as rarefactions.

## Transverse Waves

• In transverse waves, particles in the medium move perpendicular to the direction of the wave.
• Waves on a string or water surface waves are examples of transverse waves.
• These waves have peaks (crests) and troughs (valleys), which represent maximum displacement of the medium.

## Electromagnetic Waves

• Unlike mechanical waves, electromagnetic waves do not need any medium to propagate.
• They can travel through the vacuum of space since they are generated by the vibration of electric charges.
• Examples include light waves, microwaves, radio waves, X-rays and gamma rays.
• Similar to transverse mechanical waves, electromagnetic waves have peaks and troughs.

## Wave Properties

• All waves have some common properties:
• Wavelength: Distance between two consecutive corresponding points of a wave, such as from crest to crest or from trough to trough.
• Frequency: Number of wavelengths that pass a certain point each second.
• Amplitude: The maximum extent of a wave from its rest position.
• Speed: The distance a wave travels per unit of time.
• These properties help in distinguishing one type of wave from another and understanding the energy transmitted by the wave.

## Waves in Science and Technology

• Understanding waves is fundamental to many areas of science and technology such as:
• Communications: Radio and television broadcasts, mobile phone signals, WiFi connections all rely on electromagnetic waves.
• Medicine: Ultrasound (mechanical waves) is used for imaging internal body structures. X-rays (electromagnetic waves) are used to examine fractures, infections and tumors.
• Astronomy: Observations of electromagnetic waves from space can provide information about the universe.