Light Flashcards
Energy
Is the ability to do work, unit of energy is the joule
Plants use of light
To make food (photosynthesis)
Humans use of light
Solar panels, crooked radiometer
Luminous
Gives off light e.g. Sun, lightbulb, candle
Non-luminous
Do not give off light, need light to bounce off them for us to see them e.g. Book, your face, table
Light travels in straight lines
We can show this by blocking light from a bulb with a 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 light bounces off a surface
Regular reflection
Rays get reflected back at the same angle, shiny smooth surface e.g a mirror
Irregular reflection
Rough surface e.g a ball of tinfoil
Concave or diverging mirrors
Telescopes, make up and shaving mirrors, 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
Bending of light as it goes from one medium to another e.g. Air to water
Light rays are refracted towards the more dense material
