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Science 1B Chapter 5 Mindmap - Coggle Diagram
Science 1B Chapter 5 Mindmap
Properties of light
Light travels in a straight line which are called rays
A beam of light is a bundle of light rays
Light disperses in all directions
Light travels fast
Speed of light: 3(10⁸)m/sec
Luminous and Non-luminous
Luminous
Gives off light
Non-luminous
Doesn't give off light
REFLECTION
Is the bouncing of light off a surface/ light ray travelling away from the reflected surface after bouncing off the surface
Light reflected into our eyes enable us to see the object
Our eyes have a restricted angle of which light can enter
The angle of reflection is the angle between the reflected ray and the normal
Laws of reflection
The angle of reflection is equal to the angle of incidence
The incidence ray, reflection ray and the normal are all on the same plane mirror
Example: Periscope
Rough surfaces
Scatters light
Hence not being able to see our reflection on rough surfaces
Reflection on a rough surface is called a diffused reflection
Smooth surfaces
Parallel rays of light
Reflection on a smooth surface is called a regular reflection
The only time the angle of reflection is the same as the angle of incidence is when the angle of incidence is 90°
Characteristics of an image formed by a plane mirror
Image is upright
Image is the same size as the object
Image is virtual
Formed inside the mirror and cannot be formed on a screen
Image is laterally inverted (aka mirror image)
The distance between the image and the mirror is equal to the distance between the object and the mirror
INCIDENCE
Is the angle between the incident ray and the normal
Is the light ray hitting the reflecting surface
NORMAL
The normal line is based on the light ray
Is perpendicular to the surface at the point of incidence
Mirrors
Convex mirrors
Curves outwards
Used mainly in car mirrors
To maximize the volume of space that is able to be seen without moving much
Concave mirrors
Curves inwards
REFRACTION
Makes things appear to be closer to the surface than they really are
Is the bending of light at the boundary between different optical mediums due to a change in the speed of light
Optical density
Is a physical property
Affects the speed at which light travels through the medium
The denser the medium, the closer to the normal
Speed of light: vacuum > gas > liquid
Dispersion of light
White light
Made of: red, orange, yellow, green, blue, indigo, violet
Different colours bend at different angles
Violet light rays bend the most
Red light rays bends the least
Splitting of white light into its component colours is known as dispersion
Types of light and their impacts
Electromagnetic radiation
Gives off electromagnetic rays
Infrared light
Gives off infrared radiation
Thermometer scanner
Different colours for different temperatures
Harmful effects
Gets trapped in the atnosphere
Contributes to global warming/ climate change
Longer wavelength compared to Ultraviolet radiation
Ultraviolet radiation
Increases the production of Vitamin D in humans when in contact with humans
Found in sunlight
Environmentally friendly method of disinfecting items
Harmful effects
Overexposure can harm our eyes and cause skin cancer/ skin diseases
Shorter wavelength compared to Infrared radiation
Visible light
Coloured light
Harmful effects
Can cause chemical changes in some materials