q 5s Flashcards
(23 cards)
What is resonance?
Resonance is when frequency is applied to an object that is the same or close to the natural frequency of that object. This will make it start to vibrate.
Eg. putting a vibrating tuning fork near another.
one use for a convex lens
magnifying glass
two uses for concave mirrors
used in searchlights, floodlight
used as makeup mirrors
scientist to do with refraction
Snell
scientist to do with laws of electromagnetic induction
Faraday
Refractive index formula with critical angles
refractive index = 1/sin c
What is the doppler effect
The apparent change in frequency of waves due to the motion of the source or the observer
converging lens shape and use
()
used as magnifying glass / contact lens
equipment used to separate white light into its colours
prism
What is the threshold of hearing?
The lowest intensity to which the human ear can respond when f = 1 KHz
How does light travel through an optical fibre + diagram
- Light enters fibre and strikes inside of fibre at an angle greater than the critical angle.
- Total internal reflection occurs
- The ray is reflected to the opposite side and total internal reflection occurs again
- This process continues and the light travels through the fibre
Differences between a sound and light wave
Light travels in transverse waves
Sound travels in longitudinal waves
speed, wavelength, frequency triangle
speed
/
wavelength x frequency
Why are the diffraction effects of sound waves not noticeable in everyday life whereas the diffraction effects of light waves are not?
Light travel in transverse waves and need very small slits to be diffracted. Sound travels in longitudinal waves and only need an obstacle to be diffracted.
What is sound intensity?
The rate at which sound energy is passing through unit area at right angles to the direction in which the sound is travelling at that point
What is the polarisation of a wave?
Controlling the vibrations of a wave. Only transverse waves can be polarised.
complementary colours example
yellow + blue
refractive index using speeds of mediums
refractive index = speed of light in air / speed of light in medium
speed of light in air
3 x 10^8
power of a lens formula
power = 1 / focal length
focal length is in metres
conditions necessary to see a rainbow
Should have rained / raining
Sun is present / daytime
Sun must be behind us
Why use a convex mirror instead of a plane mirror on a car?
Image is smaller so more image can fit onto a convex mirror. This provides a larger field of view than a plane mirror.
doubling intensity level
increases sound intensity by 3 dB
