Waves in Matter
Wave Behaviour- Specification
,https://pmt.physicsandmathstutor.com/download/Physics/GCSE/Notes/OCR-A/5-Waves-in-Mat
ter/Definitions.pdf
,DEFINITIONS:
Amplitude: The maximum displacement of a wave from its undisturbed (equilibrium)
position.
*Colour: The colour of an object is determined by which wavelengths of light reflect from it.
All other wavelengths are absorbed.
Concave Lens: A lens that is thicker at the edges than in the centre. Parallel rays diverge
when passing through.
Convex Lens: A lens that is thicker in the centre than at the edges. Parallel rays converge
when passing through.
Diffuse Reflection: The reflection of a wave from a rough surface that results in the wave
being scattered.
Electromagnetic Spectrum: A group of transverse waves that cover a large range of
frequencies and wavelengths. The highest frequency waves in the spectrum are gamma-rays
and the lowest are radio waves.
Electromagnetic Waves: Transverse waves that transfer energy from the source of the
waves, to an absorber. They form a continuous spectrum of different frequencies and all travel at the
same speed in a vacuum.
Focal Length: The distance between the centre of a lens and its principal focus.
Foetal Scanning: A method of producing an image of a foetus in a womb through the
emission, reflection and detection of ultrasound waves.
Frequency: The number of waves passing a given point in a second. It is the inverse of the
wave’s time period.
Gamma Rays: High energy radiation rays used for detecting and treating cancers, and
sterilising food and medical implements. They can cause cell damage and mutations.
Hertz (Hz): The unit of frequency.
Infrared Radiation: A type of radiation that all objects emit and absorb. The hotter an object
is, the greater the infrared radiation it emits in a given time.
Infrared: Used for cooking food, thermal imaging and short range communications. It can
cause skin burns.
Law of Reflection: The angle of incidence must always equal the angle of reflection when a
waves reflect.
Lens: An object that forms an image through the refraction of light.
Longitudinal Waves: Waves with oscillations that are parallel to the direction of
travel/energy transfer.
Microwaves: Used for satellite communications and for cooking food. They can cause
internal heating of body cells.
Power of a Lens: Equal to the reciprocal of the focal length of a lens. Concave lenses have
negative powers whereas convex lenses have positive powers.
Principal Focus: The point before or after a lens where light rays appear to meet.
, Radio Waves: Used for television and radio signals. They can be produced by
oscillations in electrical circuits, or can induce these oscillations themselves.
*Ray Diagram: A visual representation of the path of a wave, usually around the point where
it meets a boundary. Rays are usually drawn as straight lines with an arrow pointing in their
direction of travel.
Real Image: An image produced by light-rays physically converging. Real images are ones
that can be projected onto a screen.
*Reflection: The bouncing back of a wave at a boundary.
*Refraction: The changing of speed, and consequently the direction, of a wave as it changes
medium. The wavelength of the wave will also change but the frequency remains constant.
Seismic Waves: Waves that are produced by earthquakes.
Specular Reflection: The reflection of a wave from a smooth surface.
Speed of EM Waves: All electromagnetic waves travel at the same speed in a vacuum (3 x
10⁸ m/s).
Time Period: The time it takes for one complete wave to pass a given point. It is the inverse
of frequency.
Transverse Waves: Waves with oscillations that are perpendicular to the direction of
travel/energy transfer.
*Ultrasound Waves: Waves that have a frequency higher than the upper limit of human
hearing (20kHz).
Ultraviolet: Used in energy efficient lamps, disinfecting water, and for sun tanning. It can
cause cell and eye damage that can result in skin cancer and eye conditions.
Virtual Image: An image produced by the apparent, but not actual, divergence of light-rays.
Virtual images cannot be projected onto a screen.
Visible Light: The only type of electromagnetic radiation that our eyes can detect. It is used
for fibre optic communications and photography.
Wave Velocity: The velocity at which energy is transferred through the medium. It is equal to
the product of the wave’s wavelength and frequency.
Wave: A process of energy transfer through oscillations, without medium being transferred
with it.
Wavefront: An imaginary surface representing points of a wave that are at the same point in
their cycle.
Wavelength: The distance from a point on one wave to the same point on the adjacent wave
(ie. peak to peak or trough to trough).
X-Rays: Used for medical imaging and security scanners. They can cause cell damage and
mutations.
Wave Behaviour- Specification
,https://pmt.physicsandmathstutor.com/download/Physics/GCSE/Notes/OCR-A/5-Waves-in-Mat
ter/Definitions.pdf
,DEFINITIONS:
Amplitude: The maximum displacement of a wave from its undisturbed (equilibrium)
position.
*Colour: The colour of an object is determined by which wavelengths of light reflect from it.
All other wavelengths are absorbed.
Concave Lens: A lens that is thicker at the edges than in the centre. Parallel rays diverge
when passing through.
Convex Lens: A lens that is thicker in the centre than at the edges. Parallel rays converge
when passing through.
Diffuse Reflection: The reflection of a wave from a rough surface that results in the wave
being scattered.
Electromagnetic Spectrum: A group of transverse waves that cover a large range of
frequencies and wavelengths. The highest frequency waves in the spectrum are gamma-rays
and the lowest are radio waves.
Electromagnetic Waves: Transverse waves that transfer energy from the source of the
waves, to an absorber. They form a continuous spectrum of different frequencies and all travel at the
same speed in a vacuum.
Focal Length: The distance between the centre of a lens and its principal focus.
Foetal Scanning: A method of producing an image of a foetus in a womb through the
emission, reflection and detection of ultrasound waves.
Frequency: The number of waves passing a given point in a second. It is the inverse of the
wave’s time period.
Gamma Rays: High energy radiation rays used for detecting and treating cancers, and
sterilising food and medical implements. They can cause cell damage and mutations.
Hertz (Hz): The unit of frequency.
Infrared Radiation: A type of radiation that all objects emit and absorb. The hotter an object
is, the greater the infrared radiation it emits in a given time.
Infrared: Used for cooking food, thermal imaging and short range communications. It can
cause skin burns.
Law of Reflection: The angle of incidence must always equal the angle of reflection when a
waves reflect.
Lens: An object that forms an image through the refraction of light.
Longitudinal Waves: Waves with oscillations that are parallel to the direction of
travel/energy transfer.
Microwaves: Used for satellite communications and for cooking food. They can cause
internal heating of body cells.
Power of a Lens: Equal to the reciprocal of the focal length of a lens. Concave lenses have
negative powers whereas convex lenses have positive powers.
Principal Focus: The point before or after a lens where light rays appear to meet.
, Radio Waves: Used for television and radio signals. They can be produced by
oscillations in electrical circuits, or can induce these oscillations themselves.
*Ray Diagram: A visual representation of the path of a wave, usually around the point where
it meets a boundary. Rays are usually drawn as straight lines with an arrow pointing in their
direction of travel.
Real Image: An image produced by light-rays physically converging. Real images are ones
that can be projected onto a screen.
*Reflection: The bouncing back of a wave at a boundary.
*Refraction: The changing of speed, and consequently the direction, of a wave as it changes
medium. The wavelength of the wave will also change but the frequency remains constant.
Seismic Waves: Waves that are produced by earthquakes.
Specular Reflection: The reflection of a wave from a smooth surface.
Speed of EM Waves: All electromagnetic waves travel at the same speed in a vacuum (3 x
10⁸ m/s).
Time Period: The time it takes for one complete wave to pass a given point. It is the inverse
of frequency.
Transverse Waves: Waves with oscillations that are perpendicular to the direction of
travel/energy transfer.
*Ultrasound Waves: Waves that have a frequency higher than the upper limit of human
hearing (20kHz).
Ultraviolet: Used in energy efficient lamps, disinfecting water, and for sun tanning. It can
cause cell and eye damage that can result in skin cancer and eye conditions.
Virtual Image: An image produced by the apparent, but not actual, divergence of light-rays.
Virtual images cannot be projected onto a screen.
Visible Light: The only type of electromagnetic radiation that our eyes can detect. It is used
for fibre optic communications and photography.
Wave Velocity: The velocity at which energy is transferred through the medium. It is equal to
the product of the wave’s wavelength and frequency.
Wave: A process of energy transfer through oscillations, without medium being transferred
with it.
Wavefront: An imaginary surface representing points of a wave that are at the same point in
their cycle.
Wavelength: The distance from a point on one wave to the same point on the adjacent wave
(ie. peak to peak or trough to trough).
X-Rays: Used for medical imaging and security scanners. They can cause cell damage and
mutations.
