(P1) Topic 4- Waves Flashcards
Where is the angle of incidence
Between the incident ray and the normal
Where is the angle of refraction
Between the normal and the refracted ray
Sound speeds up when it goes from air to wood. The frequency _______ and the wavelength _______
Stays the same, increases
Sound slows down when it goes from wood to air. T he frequency _____ and the wavelength ______
Stays the same, decreases
What do filters absorb
The colour they are not e.g blue absorbs all except blue
Why are things colours you see
They absorb all the other colours and reflect the one you see
What is refraction dependant upon
Wave length
What colours do objects reflect
The colours they contain e.g red object + green filter = black because green has no red light, to the red object can’t reflect
White objects _____ all colours
Reflect
Black objects ____ all colours
Absorb
What does the pinna do
Funnels sound waves into the ear canal
Where is the pinna
The outside top bit of the ear
What causes the ear drum to vibrate
Sound waves
Where is the ear drum
At the end of the ear canal
What do the vibrations of the ear drum cause
The ossicles to move
What do the movements of the staples cause
Wave-like movements in the fluid inside the cochlear
What do the wave-like movements in the cochlear stimulate
Hairs inside the cochlear, which respond to differences in frequency and pitch
What do the hair cells in the cochlear generate
Nerve impulses which are transferred to the auditory nerve
Where does the nerve impulse go from the auditory nerve
The auditory cortex
What does the auditory cortex do
Converts nerve impulses into sound
What is frequency
Sound at a different pitch
From what frequencies can humans hear
20-20,000Hz
What is Hertz a measurement of
How often something vibrates
What kind of waves are earthquakes
Seismic waves
What are the characteristics of P waves (primary waves)
Faster than S waves, compressional waves, back and forth, first to arrive after an earthquake, longitudinal
What are the characteristics of S waves
Shear waves, transversal, arrive after P waves, slower than P waves, transversal
What can ultrasound waves be produced by and what uses it
Magnetism- the crystals that use this are called manetostrictive crystals, the magnetism is called magnetostrition, and the transducers are called magnetostrictive transducers
What is the frequency of ultrasound
Over 20,000Hz
Why is ultrasound used for investigating the sea floor
Because the distance is too great to see what is at the bottom with light and light refracts in water.
Why is ultrasound used in medial scans
To reduce the amount of operations
What is the frequency of infrasound
Below 20Hz
Transverse waves
Oscillations are perpendicular to direction of wave travel
Longitudinal waves
Oscillations are parallel to direction of wave travel
Transmission
Wave passing through
Reflection
A wave bouncing off
Absorption
A transfer of energy from a wave to a medium
Refraction
A wave changing speed and direction
Calculation for wave speed
Wave speed = frequency x wavelength
