Light Flashcards
(20 cards)
Energy
Is the ability to do work i.e. Move. Unit of energy is the joule
Plants use of light
To make food (photosynthesis)
Photo- light
Synthesis- to make
Human use of light
Solar panels
Crooke’s radiometer
Luminous
Objects that give off light
Non luminous
Objects that do not give off light, and need light to bounce off them for us to see them
Light
Is a form of energy
Light travels in straight lines
We can show this by blocking light from a bulb with card
Light does not travel around corners
Blocking light leads to shadows
Solar eclipse
Occurs when the moon passes between the sun and the earth
Lunar eclipse
Occurs when the earth is between the sun and the moon, the moon is in the earths shadow.
Reflection of light
Occurs when it bounces off a surface
Regular reflection
Shiny smooth surface, the Rays are reflected back at the same angle
Irregular reflection
Rough surface e.g. A ball of tinfoil
Concave or diverging mirrors
Telescopes, makeup,shaving, can enlarge the image
Convex or converging mirrors
Side mirror in cars, security mirrors in shops
Small, upright image with a wider field of vision
Refraction
The bending on light as it goes from one medium to another e.g. Air to water.
Lights rays are refracted towards the denser material
Convex or converging lens
Used to bring rays together
Used to fix long sightedness, or hypermetropia
Concave or diverging lens
Used to spread Rays apart
Used to fix short sightedness, or myopia
Whit light
Not really white, is a mixture of the 7 colours of the spectrum
Dispersion
Is the splitting of white light into its constituent colours due to refraction
