Science - Light
What is light?
Light is a form of energy
What are luminous objects? Give an example
They make their own light, for example, the sun
What are non luminous objects? Give an example
They reflect light, for example, the moon
State a property of light
Light travels in striaght lines
Light travels faster than sound
This is light bouncing back off a surface
What is diffuse reflection?
This happens when light bounces off a rough surface in all directions
What is regular diffusion?
This happens when light bounces in one direction off a smooth surface
What is a periscope?
A periscope has two mirrors at opposite ends of a tube
It is used to see over things
Give a use for a periscope
To see over a high wall or crowds
Used in submarines
What is a shadow?
This is a dark area behind something where the light cannot reach
What is a medium?
This is a solid, liquid or gas which allows waves to travel through it
What is dispersion?
This is the splitting of light into the seven colours of the spectrum using a glass prism
List the seven colours of the spectrum
Ring Out Your Great Bells In Victory
List the primary colours
List the secondary colours
Refraction is the bending of light as it passes from one surface to another eg. from air to glass
State the function of a lens
To reflect or bend light
List the two types of lens
Convex lens is for long sighted people. It focuses the light so that the image is formed back onto the retina
Concave lens is for short sighted people. It focuses the light so that the image is formed further forward onto the retina
Name the part labelled A
Name the part labelled B
Name the part labelled C
Name the part labelled D
Name the part labelled E
Name the part labelled F
State the function of the iris
To control the amount of light entering the eye
State the function of the pupil
To allow light enter the eye
State the function of the lens
To make a sharp picture on the retina
It focuses light onto the retina
State the function of the retina
To change the picture into nerve messages
State the function of the optic nerve
To carry messages from the eye to the brain
State the function of the ciliary muscle
To change the shape of the lens and allow us to see things either close up or far away
State the function of the cornea
To allow light into the eye and bend the light rays
What are cones?
These are nerve cells located on the retina that allow us to see colours
What are rods?
These are cells that are found in our eye that allow us to see in black and white
Science - Light