PHYSICS OF WAVES
Waves transfer energy without transferring matter
Transverse wave: vibration is at right angles to the direction of energy transfer
Made by moving the free end of the spring from side to side
Water ripples are produced by something vibrating up and down vertically but
the ripples move out horizontally
Particles in rope vibrate in a fixed position and energy are transferred from one
end to the other
Longitudinal wave: the oscillations are parallel to the direction of energy transfer
Made by pushing the free end of the spring back to forth, along the length of the
spring
Rarefaction: region of a sound wave where the particles are further apart -> lower
pressure
Compression: region of a sound wave where the particles are pushed close
together -> higher pressure
Wavefront: a line joining adjacent points on a wave that are all in step with each
other
Speed: how fast the wave travels
Amplitude: maximum displacement from mean
position
Frequency: number of oscillations in 1 second or
number of compressions produced per second
Transverse Longitudinal waves Wavelength: length of 1
waves complete wave or between 2
Light Sound waves successive compressions
Electromagnetic
Speed = Wavelength x
waves
Frequency v = fλ
Water waves
Vibrating string Waves can undergo
Reflection at a plane surface
Refraction due to a change of speed
Deep to shallow Shallow to deep
, PHYSICS OF WAVES
Speed decreases Speed increases
Wavelength decreases Wavelength increases
Frequency stays the Frequency stays the same
same
Diffraction through a narrow gap
a, gap > wavelength -> less diffraction
b, gap = wavelength -> maximum diffraction
c, gap < wavelength -> reflected, no diffraction
Light
Optical image by plane mirror
Same size as object
Same distance behind mirror as object in front
of it
Left-right inverted
Virtual
Angle of incidence = angle of reflection
Snell’s Law: n = sin i/ sin r
Refractive index: quantity that describes how much light is slowed down
n = speed of light in vacuum / speed of light in medium
Light travels to a more dense material -> bends towards normal -> incident
angle > refracted angle
Light travels to a less dense material -> bends away from normal -> incident
angle < refracted angle
Critical angle: the angle at which light ray will be totally internally reflected
Waves transfer energy without transferring matter
Transverse wave: vibration is at right angles to the direction of energy transfer
Made by moving the free end of the spring from side to side
Water ripples are produced by something vibrating up and down vertically but
the ripples move out horizontally
Particles in rope vibrate in a fixed position and energy are transferred from one
end to the other
Longitudinal wave: the oscillations are parallel to the direction of energy transfer
Made by pushing the free end of the spring back to forth, along the length of the
spring
Rarefaction: region of a sound wave where the particles are further apart -> lower
pressure
Compression: region of a sound wave where the particles are pushed close
together -> higher pressure
Wavefront: a line joining adjacent points on a wave that are all in step with each
other
Speed: how fast the wave travels
Amplitude: maximum displacement from mean
position
Frequency: number of oscillations in 1 second or
number of compressions produced per second
Transverse Longitudinal waves Wavelength: length of 1
waves complete wave or between 2
Light Sound waves successive compressions
Electromagnetic
Speed = Wavelength x
waves
Frequency v = fλ
Water waves
Vibrating string Waves can undergo
Reflection at a plane surface
Refraction due to a change of speed
Deep to shallow Shallow to deep
, PHYSICS OF WAVES
Speed decreases Speed increases
Wavelength decreases Wavelength increases
Frequency stays the Frequency stays the same
same
Diffraction through a narrow gap
a, gap > wavelength -> less diffraction
b, gap = wavelength -> maximum diffraction
c, gap < wavelength -> reflected, no diffraction
Light
Optical image by plane mirror
Same size as object
Same distance behind mirror as object in front
of it
Left-right inverted
Virtual
Angle of incidence = angle of reflection
Snell’s Law: n = sin i/ sin r
Refractive index: quantity that describes how much light is slowed down
n = speed of light in vacuum / speed of light in medium
Light travels to a more dense material -> bends towards normal -> incident
angle > refracted angle
Light travels to a less dense material -> bends away from normal -> incident
angle < refracted angle
Critical angle: the angle at which light ray will be totally internally reflected
