Download Science - John Madejski Academy

Year 7 Science: Waves Knowledge Organiser
Longitudinal waves eg. sound
- parallel to the movement of the
source
- vibrates left and right
Transverse waves eg. light and waves
- right angles to the movement of
the source
- vibrates up and down
Peak
Amplitude
loud
quiet
Frequency
low pitch
high pitch
Cochlea
Auditory
nerve
Ear drum
How do we hear?
Sound is produced by vibrations
Vibrations create sound waves in the air
Our ear flaps collect sound waves and pass them
on to a membrane called the ear drum
The eardrum vibrates and passes on the vibrations
to the inner ear, to the three small bones
The three small bones vibrate and pass on the
vibrations to the cochlea
The cochlea is the part of the inner ear that
contains tiny hairs, which vibrate then send
messages to the brain
Loudness is measured in decibels (dB)
Wave
Name
Ear canal
Energy
rating
Used for
Dangers
Low
Communications
Not dangerous
Low
Mobile phones
and heating food
Low risk
Moderate
Remote controls,
to heat things, to
detect people
To see things and
photography
Some risk (can
burn)
Sunbeds, to kill
bacteria, in
security marking
Medicine, to see
through things
Sun burn, skin
cancer
Radio
Sound wave
Microwaves
Ear bones
Infrared
Outer ear
Moderate
Visible light
Moderate
Ultraviolet
High
X Rays
High
Gamma
Rays
Medical
treatment, to
sterilise things
Can damage the
eye
Very dangerous,
long exposure
leads to cancer
Very dangerous,
can kill cells and
cause cancer
Year 7 Science: Waves Knowledge Organiser
Pupil- Lets light into the eye
Cornea- Protects the pupil
Lens- Bends rays of light to form a clear image
Iris- Controls the size of the pupil
Retina- Where the image is formed
Optic nerve- Sends messages to the brain
Iris
Cornea
Pupil
Luminous- transfers light energy
Non luminous- does not transfer light energy
Absorb- energy from the light is used up in the material
Reflect- light bounces off surface
Transmit- light travels through the material
Angle of incidence = Angle of reflection
Retina
Lens
Refraction
Light ray slows and bends
toward the normal due to
entering a more dense medium
Dispersion
Low frequency
Light ray speeds up and bends away
from the normal due to entering a
less dense medium
High frequency
Primary colours
Secondary colours
Red
Magenta (Blue + Red)
Blue
Cyan (Blue + Green)
Green
Yellow (Red + Green)
Wave slows down but is
not bent, due to entering
along the normal
Red
Filter
Magenta
Filter
Reflects red, absorbs
all other colours
Absorbs all colours
Reflects all colours
Red
Filter
Green
Filter