light
electromagnetic radiation that you can see
radient energy
what kind of energy does light carry?
phones/communication
example of radio waves
microwave/spacecraft communication
example of microwaves
heat sensitive pictures
example of infrared waves
photosynthesis
example of visible light
black light/sun/tanning beds
example of ultra-violet waves
bones
example of x-rays
earth's atmosphere
example of gamma rays
frequencies and wavelengths
what determines the difference between the electromagnetic spectrum?
1 - amplitude 2 - persons perception of light 3 - distance from light source 4 - eye sensitivity to light
what are three things that change how bright/intense a light is?
vacuum
what medium does light travel through fastest?
solid
What medium does light travel through slowest?
in a vacuum, the molecules are further apart and solids are closer together so light travels faster in a vacuum because there are fewer molecules that the light has to pass through
why does light travel through a vacuum faster that a solid?
light transmits through glass
what is an example of evidence that light transmits through materials?
light is absorbed by solar panels and black fabric
what is an example of evidence that light absorbs into materials?
light reflects off mirrors and white clothing
what is an example of evidence that light reflects off materials?
transparent - a material that allows almost all the light striking it to pass through and through which the objects can be seen clearly translucent - a material that allows most of the light striking it to pass through but through which the objects appear blurry
what are two types of material that light can transmit through? explain their meaning?
light-blocking curtains/wood/counters/floor
what are some materials that are opaque?
light bounces off you, strikes the mirror, and bounces back to your eye
how are you able to see your reflection in a mirror?
law of reflection
when a wave is reflected from a surface, the angle of reflection is equal to the angle of incidence
virtual image
an image that forms from light rays that diverge
concave mirror
a mirror that curves inward
convex mirror
a mirror that curves outward
convex - outward
concave - inward
what's the difference between concave and convex?
real image
an image that forms where rays converge
regular reflection
reflection off a smooth hard surface
diffuse reflection
reflection off a rough surface
scattering
when light waves traveling in one direction are made to travel in many directions
refraction
the change in direction of a wave as it changes speed while moving from one medium to another
lower index - faster travel of light
higher index - slower travel of light
how does the speed of a wave change as the index of refraction increases?
If light enters any substance with a higher refractive index (such as from air into glass) it slows down. The light bends towards the normal line. If light travels enters into a substance with a lower refractive index (such as from water into air) it speeds up. The light bends away from the normal line.
how does a light ray direction and speed change as it passes through air-glass-air
concave - diverge
convex - converge
how do convex and concave lenses change how an object is seen?