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Physics - MUS
Physics - Music Section
Question | Answer |
---|---|
What does amplitude mean? | The maximum displacement from the undisturbed portion of the wave to the crest |
What does frequency mean? | The number of waves per second |
What is period? | The time it takes for one wave to pass. Can be measured from peak to peak, trough to trough |
What is the wavelength? | The length of a wave from peak to peak, trough to trough etc. |
Name all the types of radiotion in the electromagnetic spectrum in order from longest to shortest wavelength | Radio waves, Microwaves, Infra-Red, Visible Light, Ultra-Violet (UV) Rays, X-Rays and Gamma Rays |
Give three uses for radio waves | Radio (music), television and mobile phone signals |
Give 2 uses for microwaves | Satellite singals (e.g. satellite tv) and microwave ovens |
Give 2 uses for infra-red light | Night Vision, Data transfer (e.g. mobile phones) |
Give 2 uses of U/V light | U/V telescopes, Security Stamps |
What is so dangerous about U/V light? | It can damage the skin and lead to skin cancer |
What can X-Rays be used for? | Producing images of the skeleton |
Give 2 uses for gamma rays | Sterilisation and killing cancer cells |
What is so dangerous about gamma rays? | They can make cells mutate and therfore induce cancer |
What is the wave equation? | Velocity = frequency x wavelength (lambda) |
What is the diference between light and sound? | Light is a transverse wave while sound is a longitudal wave |
Sound can be described in terms of the... | displacement of molecules |
What are standing waves? | A wave between two points that appears to be stationary because the wave reflects and induces a phase change of 90 degrees |
What is a wavefront? | The leading edge of a single pulse |
What is superposition? | When two waves collide causing constructive or destructive interference |
If two waves are coherent, they are... | of the same frequency and with a constant phase relationship |
In a standing wave what is a node or anti-node? | A node is a point where there is no change and a anti-node is where there is maximum change (e.g. a peak or trough on a wave graph) |
What are resonant frequencies? | Fixed frequencies at which the tube or object gives a sound at |
What does the fundemental frequency mean? | The lowest resonant frequency that can be produced, i.e. one standing wave |
Why do stringed instruments have sound boxes? | The string vibrating itself affects very little air (not much air is displaced). The sound box resonates with the string meaning more air is displaced so a louder sound |
What us the wavelength of the lowest frequency? | lambda = 2l where l is the length of the string/tube |
In a string, the greater the tension the greater the ... | speed |
How does the mass-per-unit length of a string affect the speed | The greater the mass-per-unti length the slower the speed |
Give the equation that relates speed, tension and mass-per-unit length | p.150 text book |
What is phase difference? | Where waves reach their peaks and troughs at different times |