Test 1 Y9 Flashcards
What is the function of the cornea
It controls how big your iris can get
What is the function of the iris
focus’ on what you can see
What is the function of the pupil
Like a hole that lets light into the lens and retina
What is the function of the lens
The lens is able to adjust to form a picture for us to see
What is the function of the retina
It contains 130 million light sensitive cells
What is the function of the optic nerve
It carries the signal from the eye to the brain
What happens when a ray of light enters a see through block at 90°
The light won’t change direction
What happens when a ray of light enters a see through block at any angle other than 90°
The light changes direction
What happens when light moves from air to glass
It slows down
What happens when light moves from glass to air
It speeds up
How do lenses work
Lenses work because their curved surface refracts the light and bends it
If both sides of a lens are pointed out what is it
A converging lens
If both sides of a lens are pointing in what is it
A diverging lens
When a light ray passes through a convex/ converging lens what happens
They crossover
When light passes through a diverging/concave lens what happens
They spread out
White light is split into the the colours of a rainbow through a prism what is this called
Dispersion
How does dispersion happen
The violet light slows down and the red light speeds up
What is the order of the em spectrum from high to low
Gamma
X-ray
UV
Visible
Infrared
Microwave
Radio
What does em stand for
Electro magnetic
What are the dangers and uses of gamma
They can pass through bones or teeth and cause cancer but also heals cancer
What are the dangers and uses of X-ray
They can cause blocked blood vessels and bone cancer but are very useful in hospitals to check for Brocken bones and pregnancy
What are the dangers and uses of uv
These can cause skin cancer and sunburn
What are the dangers and uses of visible light
It helps us see our surroundings but can cause sunburn if excessive
What are the dangers and uses of infrared
IR is used for cooking and remote controls but can cause damage to the skin
What are the dangers and uses of microwave
Heating foods but can cause skin burn
What are the dangers and uses of radio
They are used for communication and broad casting
What is in the outer ear
Pinna, ear canal and ear drum
What is the function of the outer ear
It collects and funnels sound waves
What are the 3 small bones in the ear called
The hammer, stirrup and anvil
What is the function of the middle ear
It amplifies sound
What is the function of the inner ear
The inner ear simply helps you hear better
Can air travel through vacuum
No
What is the equation for speed
Speed= distance/time
What is the equation for time
Time = speed/distance
What is the equation for distance
Distance = time x speed
What is frequency measured in
Hertz
Pressure = ?
Force/area
What are the units for pressure
N/cm2 and n/m2
What is conduction
The transfer of heat through solids
What is convection
When heat is transferred through gas and water
What is radiation
the matter that is emitted in the form of electromagnetic waves
How is background radiation caused
It is caused by radioactive materials found mostly rocks and soil
What are three 3 types of radiation in order of radioactivity
Alpha (least)
Beta
Gamma (most)
