P12 Waves Flashcards
What are the properties of longitudinal waves
Show areas of compression and rarefaction
Directions of vibrations are parallel to direction of wave
Properties of transverse waves
Has the vibrations perpendicular to direction of flow
What is the amplitude of a wave
Maximum displacement of a point on a wave away from itโs undisturbed position
What is the wavelength of a wave
Distance from a point on one wave to the equivalent point on the adjacent wave
What is the frequency of a wave
Number of waves passing a point each second
What is the equation for period
T = 1/f Period = 1/ frequency
Wave speed equation
V = f x ฮป Speed = frequency x wavelength
What happens if a light wave hits a boundary along the normal
It slows down but is not refracted
What happens if a light wave hits a boundary at an angle
The wave slows down and changes direction - it refracts
How to construct a ray diagram
1.Draw boundary and normal ( at 90ยฐ to boundary )
2. Draw incident ray that meets normal at the boundary ( angle between normal and incident is the angle of incidence )
3. Draw refracred ray on other side of boundary.
If material is optically denser than first: refracted ray bends towards the normal ( angle between normal and refraction is smaller than incidence )
If material is less optically dense: angle of refraction is larger than angle of incidence
How do sound waves actually make noise
They vibrate through solids causing vibrations
What is the range of normal human hearing
20Hz - 20kHz
What are ultrasound waves
They have a frequency higher than human hearing
They can be used for medical imaging and industrial imaging
How are ultrasound waves used for imaging
They are partially reflected when they meet a boundary between 2 media. The time taken for reflections to meet detector can be used to determine how far away the boundary is
What 2 waves do earthquakes produce and how are they different
P - waves: longitudinal, travel through solids and liquids
S - waves: transverse, cannot travel through a liquid