Light & Sound Flashcards
Name the properties of light
- it is a form of energy
- it travels as a wave, electromagnetic wave
- reflects off surfaces
- speed of light 300 000 km per second
When light hits a surface it may be
- transmitted through it
- reflected off it
- absorbed into it
What is the law of reflection
Angle of incidence = angle of reflection
i = r
What is refraction
Refraction is the bending of light
Higher refraction index means
That light bends towards the normal
Lower refractive index
Light bends away from the normal
Concave lenses
A lens that curves inwards. This causes light to diverge, or spread. They spread parallel light rays as though the rays have come from a point behind he lens. Only produces images that are smaller , upright and virtual.
Convex lenses
A lens that is thicker at the centre. They cause light rays to come together, or converge. This is also know as a magnifying glass when held close to an object.
ROYGBIV
Red Orange Yellow Green Blue Indigo Violet
How can white light be turned into a rainbow
When a white light is refracted through triangular prism crystal or drop of water
How is sound produced
Vibration
How does sound travel
Longitudinal waves
Frequency
The numbers of waves passing a point every second
Hertz - measurement
High f = high pitch
Low f = low pitch
Amplitude
The force of a compression
Low a = soft sound
High a = loud sound
Longitudinal wave
A wave in which the vibration is in the same direction that the wave is traveling
Compression
A region of high pressure where particles are close together
Rarefaction
A region of low pressure in which particles are far apart
Transverse wave
A wave where the vibration is at right angles to the direction the wave is traveling
Beach wave up and down
Angle of incidence
An angle the incoming Ray makes with the the normal
Angle of reflection
The angle a reflected Ray makes with the the normal
Angle of refraction
The angle the refracted Ray makes with the normal
Diffuse reflection
Reflection of light in many directions from an uneven surface
Incident Ray
Incoming Ray
Refractive index
A measure of how easily light passes through a substance
Regular reflection
Reflection of light from a smooth surface such as still water or mirror. Produces clear image
Cornea
A transparent covering over the iris. It bends light into the lens
Focal length
The distance from a lens to its focus
Lens
In the eye it is a flexible structure the enables light to be focused on the retina
Long - sightedness
Hyperopia
Inability to focus on close objects because the eyeball is to long
Optic nerve
A nerve that carries that carries an electrical signal from the retina to the brain
Real image
An image formed when rays of light actually meet
Retina
Nerve tissue at the back of the eye. Consists of cone and rod cells, light is converted into an electrical signal here
Short - sightedness
Myopia
Inability to focus on long distant objects as the eyeball is to small
Pupil
An opening in the iris that determines the amount of light entering the eye
Sclera
White of the eye
Iris
Coloured part of the eye
Aqueous humour
Water fluid produced by the ciliary body to lubricate the lens and cornea
Vitreous humour
Clear fluid between the lens and retina
What is the top of the wave called
Crest
What is the bottom of the wave called
Trough
What are the primary colours
Red green blue
What are the secondary colours
Cyan magenta yellow
Ciliary body
Connected to the lens. Muscles in the body allow the shape of the lens to change
Chorid
Has a rich blood supply and nourishes the retina
Fovea
Responsible for central vision
