Light and Sound Flashcards
What is the Law of Reflection?
The angle of the reflected ray is the angle of the incident ray.
The angle that a ray of light is shone at a mirror is the angle that it will be reflected at.
Refraction of light
Bending of light caused by passing through different transparent substances at an angle
What happens to light when it refracts into opaque objects?
The light is absorbed
What happens to light when it passes through a converging lens? (connecting)
They refract towards the normal
What happens to light when it passes through a diverging lens? (diverge)
It refracts away from the focus
Where is the angle of refraction measured?
Between the normal and refraction in the object
Where is the angle of incidence measured?
Between the normal and the incident ray
What principle does an optical fibre use?
Total internal reflection
List 4 parts of the eye and their functions.
Cornea - refracts the light to focus on the retina
Pupil - allows light to enter your eye by changing size
Lens - focuses light correctly on the retina
Retina - receives light from the lens and converts it into signals for the brain
Iris - controls the pupil
What is the splitting up of white light into colours called?
Dispersion
Why does dispersion occur?
Each colour is refracted differently
What happens when green light hits a white object?
All the other colours are absorbed, except for green which is reflected into our eyes for us to see.
What are the two ways to make colours?
Addition and subtraction
What is addition?
A way to make colours by adding colours together to get the wanted colour
What is subtraction?
A way to make colours by mixing different colours together
How do sound and light travel?
In waves
Where can’t sound travel?
In places without air
How fast does sound travel per second at 0 degrees?
330 metres
What is light a part of?
The electromagnetic spectrum
What is the wavelength of visible light?
380 - 700 nanometres
The shorter the wavelength of radiation…
the higher the energy of their waves.
What happens to a pupil when a person works from dark to light?
The pupil will expand to allow more light in then contract in the light
What are the primary colours of light?
Red, green and blue
What can and can’t sound travel through?
Sound can’t travel through empty vacuums
Sound can travel through solids, liquids and gases
Does light or sound travel faster?
Light waves
Explain refraction
The bending of light as it passes from one transparent substance to another
What is the use of convex and concave lenses?
Convex: correction of long-sight problems
Concave: The correction of short-sight problems
What do red and white objects look like in green light?
Red = black
White = green
How do we see colour?
Through the cone cells on the retina
What is the difference between transverse and longitudinal waves?
Transverse waves cause the medium to move perpendicular to the direction of the wave. Longitudinal waves cause the medium to move parallel to the direction of the wave.
What is an example of a transverse wave?
Ripples on water
What is an example of a longitudinal wave?
Sound waves
