# Waves

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• Waves
• Wave Properties: Refraction
• Refraction is the change of direction in light due to it passing through a median of different density
• The light ray changes direction towards the normal meaning the angle of refraction (r) is smaller than the angle of incidence (i)
• When exiting the median, r is greater than i
• Measuring Waves
• The amplitude of a wave is the distance between any trough or peak and the middle of the wave
• The wavelength is the distance from peak to peak or from trough to trough
• Wave Speed: Wave speed = frequency x wavelength
• The Nature of Waves
• There are two types of wave:
• Mechanical Waves: These include sound waves, water waves and seismic waves
• These waves are vibrations and require a median to pass through
• Sound waves are longitudinal meaning that the vibrations are parallel to the direction in which the wave is travelling
• Electromagnetic waves: These incleds light waves, radio waves and microwaves
• All these waves travel at roughly 300,000,000 metres a second and do not require a median to pass through
• All electromagnetic waves are transverse waves meaning the vibrations are perpendicular to the direction in which te wave is transferring energy
• Wave Properties: Diffraction
• Diffraction is the spreading of waves when passing through a small gap or past an obstacle
• The smaller the gap, the more the waves spread out
• Wave Properties: Reflection
• The line perpendicular to the reflection pane is the Normal
• The angle of incidence is the angle between the incident ray and the normal
• The angle of reflection is the angle between the reflected ray and the normal
• The incident ray is the ray of light that will be reflected
• Angle of incidence = angle of reflection
• Sound
• Sound waves are just vibrations of particles
• An object vibrating in air will make the layers of air near it vibrate, they will make other layers of air vibrate and so on and so on
• Sound cannot pass through a vacuum
• Increasing the loudness of a sound increases the amplitude of the wave
• Increasing the frequency of the sound increases its pitch