Sound And Light Chapter 4

Front 1

what are 3 things that can happen when light hits an object?

Back 1

- reflection: when light bounces off the object

- absorption: when light is changed to a different form of energy by an object.

-transmission: light passes right through

Front 2

what happens to light when it hits a material that is opaque?

Back 2

opaque material reflects of absorbs all of the light that strikes it.

Front 3

what is similar and different between transparent and translucent?

Back 3

A transparent material transmits all of the light that strikes it without scattering it , so you can see objects clearly.

A translucent material scatters the lights as it passes through it, so things look blurry through it.

Front 4

why do objects appear to be different colors?

Back 4

you see an object as the color of the light it reflects.

Front 5

what happens if you shine one color of light on an object that is another color?

Back 5

objects can look different under colored light. An orange object will appear black under a blue light because it only reflects orange light ,absorbs all other including blue

Front 6

define primary colors.

Back 6

three colors that can be used to make any other color are called primary colors.

Front 7

what are secondary colors?

Back 7

any 2 primary colors combined in equal amount produce a secondary color.

Front 8

what are complimentary colors?

Back 8

any 2 colors that combine to form white light are called complimentary colors.

Front 9

what is a pigment and what happens when you combine the 3 primary colors of pigment?

Back 9

pigments absorb some colors and reflect others. When you combine the 3 primary colors of pigment, you get black.

Front 10

describe the 2 types of reflection

Back 10

regular reflection occurs when light hits a smooth surface and the rays are reflected at the same angle, and produces a sharp image.

Diffuse reflection occurs when light hits a bumpy surface and light is reflected in many directions.

Front 11

what are the orientations of virtual and real images?

Back 11

virtual image are right-side up and appear to be behind the mirror.

Real images are upside-down and form when rays accidentally meet at a point. The image can be larger or smaller than the actual object.

Front 12

describe what image you will see in different types of mirrors

Back 12

- plane mirror a flat mirror that produces an image that is right-side up and the same size as the object being reflected

-concave mirror a mirror with a surface that curves inward. It can produce virtual or real images. If the object is further than the focal point then it forms a real image. If the object is closer than the focal point then it forms a virtual image.

- Convex mirror a mirror with a surface that curves outward. It always forms virtual images

Front 13

what kind of mirror has a flat surface?

Back 13

plane mirror

Front 14

how can you get different images from a concave mirror?

Back 14

If the object is further than the focal point then it forms a real image. If the object is closer than the focal point then it forms a virtual image.

Front 15

define optical axis and focal point

Back 15

the optical axis is an imaginary line that divides a mirror in half. The focal point is the point at which rays parallel to the optical axis reflect and meet.

Front 16

what measures the amount a ray bends when it passes from one medium to another?

Back 16

the index of refraction

Front 17

how does a prism work?

Back 17

a prism refracts different wavelengths of light by different amounts and thereby separates the colors into a rainbow

Front 18

how does mirage form?

Back 18

when light refracts as it moves from the hot air near the ground to cooler air above, a mirage is formed

Front 19

what is a lens?

Back 19

a lens is a curved piece of glass that is used to refract light

Front 20

describe the shapes of concave and convex lenses and what each do to light rays

Back 20

- concave lens: thinner in the center than at the edges. light rays are bent away from the center of the lens. It can produce a virtual image

-convex lens: thicker in the center than at the edges. Light rays are bent towards the center of the lens. The type of image depends on the position of the object in relation to the focal point.

Front 21

name and describe the different parts of the eye

Back 21

seeing light notes #9

Front 22

if a person has trouble distinguishing colors, which part of the eye is defective?

Back 22

the iris

Front 23

what carries the signal from the cells of your eye to the brain?

Back 23

optic nerve

Front 24

what shape is the lens of your eye?

Back 24

convex

Front 25

name and describe the 2 types of light-sensing cells

Back 25

- rods: detect black, white, and shades of grey. Allows you to see at night because they can detect small amounts of light.

-cones: detect color. There are separate types to detect different colors: red, green, and blue. Only work in bright light.

Front 26

describe what happens to light rays as it enters your eye

Back 26

as light enters your eye it is refracted slightly by the cornea, then it passes through the pupil, and is refracted more by the lens. Then it passes through the fluid inside your eyeball and forms an image on your retina. The light is detected by your rods and colors are detected by your cones, ans signals are sent to your brain.

Front 27

if a person is nearsighted, what is the distance they can see?

Back 27

they can see nearby objects but objects at a distance appear blurry

Front 28

if a person is farsighted, where do they have trouble seeing?

Back 28

they can see distant objects, but nearby objects can appear blurry

Front 29

how can you correct nearsightedness and farsightedness?

Back 29

you can use glasses or contact lenses

Front 30

how do objects become magnified?

Back 30

objects become magnified by using telescopes and microscopes

Front 31

how do the different kinds of telescopes work?

Back 31

- refracting telescope: consists of 2 convex lenses at each end of a tube. The large lens gathers the light and forms a real image. The small lens focuses the red light so you can see it

-Reflecting telescope: consists of a concave mirror, a plane mirror, and a convex lens. The large concave mirror collects the light and forms a real image. The plane mirror reflects the image towards the lens, which focuses it so you can see it.

Front 32

which telescope uses lenses to magnify images?

Back 32

refracting

Front 33

what is the function of a microscope?

Back 33

a microscope forms enlarged images of tiny objects

Front 34

which type of lens is used in magnifying lens?

Back 34

convex

Front 35

why is laser light only one color?

Back 35

they all have the same wavelength (color)

Front 36

what happens to light as it enters a prism?

Back 36

it will bend but not separate because it is only one color

Front 37

describe what a hologram is

Back 37

a 3-dimensional photograph created using the light from a laser

Front 38

how do optical fibers carry light long distances?

Back 38

using the total internal reflection (this occurs when light travels nearly parallel to the surface, all of it gets reflected.)

Front 39

describe different ways that light can be used for communication

Back 39

optical fibers carry cleaner signals than copper wires. They are also thinner than copper wires, so more can be placed in the same space underground. They are used for telephones, computer networks, and cable TV because they provide better signals and are less expensive.