Properties of light

Front

Electromagnetic wave

Back

a type of wave that carries energy through space and are created by the movement of electrically charged particles. These waves do not require a medium to travel through, meaning they can move through a vacuum, such as space.

Front

Absorption

Back

a process when light hits a material and its energy is taken in by the material, usually increasing the material's temperature or changes its energy in some way.

Front

What do opaque objects do?

Back

Opaque objects absorb light and don't let it pass through. e.g black clothing absorbs most of the light it hits and turns it into heat, making it feel warmer in sunlight.

Front

Explain how we see colour

Back

When light hits an object, the object absorbs some wavelengths and reflects others. The reflected light is what we see.

For example, a red apple absorbs all colors except red—red is reflected, so our eyes see it as red.

So, color is basically the light that isn't absorbed by the object.

Front

List 3 applications of absorption

Back

• Solar panels absorb sunlight and turn it into electricity

• Blackout curtains block light by absorbing it, keeping rooms darker

• Coloured clothing absorbs some wavelengths of light while reflecting others, which is why clothes appear to have different colours

Front

Reflection

Back

a process when light bounces off a surface e.g a mirror reflects light so clearly you can see an image of yourself

Front

A smooth surface reflects...

A rough surface reflects...

Back

• A smooth surface reflects light in a straight, organised way creating clear images

• A rough surface reflects light in all directions creating scattered, blurry reflection or none at all. This is why you can see the paper but not your reflection

Front

What is:

The angle of incidence?

The normal?

The angle of reflection?

Back

the angle the incident ray/incoming light makes with a line perpendicular to the surface

a line perpendicular to the surface

the angle the reflected ray/reflected light makes with a line perpendicular to the surface

Front

The Law of reflection

Back

the angle of incidence = the angle of reflection

i = r

Front

Main application of reflection?

Explain how each of the 2 work

Back

The main application of reflection is seen through mirrors. The 2 types are convex and concave mirrors.

Convex mirrors are curved outward and reflect light outwards allowing you to see more of the scene.

Concave mirrors are curved inwards and reflect light inwards to a focus point, making images larger.