Chapter 29: Reflection and Refraction

What happens to light when it strikes a metal surface?

All of the light is reflected back through original medium.

Angle between an incident ray and normal to surface is what?

Angle of Incidence

Angle between reflected ray and normal to surface is what?

Angle of Reflection

Explain how a prism separates white light into colors.

Blue light slows down more than red so blue light is bent more than red. When this happens twice the effect is enough to see the rays dispersed

This mirror can be both real or virtual image and curves inward.

Concave

This mirror bends outward and is always a virtual image.

Convex

The minimum angle of incidence for which a light ray is totally reflected within a medium is what?

Critical Angle

The reflection of waves in many directions from a rough surface is what?

Diffuse Reflection

The separation of light into colors arranged according to their frequency by interaction with a prism is what?

Dispersion

The path drawn as a straight line arrow of the incident wave(light wave that strikes boundary) is what?

Incident Ray

Upside down is?

Inverted

When light strikes a flat mirror at a certain angle, predict the path of the reflected light.

It will be the same as the first angle but in opposite direction.

The angle of incidence for a wave that strikes a surface is equal to the angle of reflection is what law?

Law of Reflection

Give three examples of uses for optical fibers

Mechanics use them to look inside engines, physicians used them to look inside a patient's body, and communications use them to replace copper telephone wires and underseas cables

A floating image that appears in the distance and is due to the refraction of light in earths atmosphere is what?

Mirage

If light had the same speed in air and in water, would light be refracted in passing from air into water? Explain

No. No change in speed=no refraction

A line perpendicular to a surface is?

Normal

The line drawn perpendicular to the "mirror" line is the __________.

Normal

When light slows down it bends toward the what?

Normal

A transparent fiber, usually glass or plastic that can transmit light with length by means of total internal reflection is?

Optical Fiber

This mirror is always virtual and is flat.

Plane

What is the orientation of a ray in relation to the wave front of a wave?

Ray is perpendicular to the wave front

This image is reversed and formed by converging light rays, can be displayed on screen,inverted.

Real Image

When waves interact with matter, they can be __________,transmitted or a combination of both.

Reflected

The way a reflected wave is drawn is what?

Reflected Ray

An arrow pointing away from the mirror indicates a _____________ ray.

Reflection

The bouncing back of a particle or wave that strikes the boundary between two media is what?

Reflection

When a wave reaches a boundary between two media, usually some or all of the wave bounces back into the first medium. This is called _____________.

Reflection

How are reflection and refraction different?

Reflection occurs when the waves do not go through the new medium and bounce back while refraction occurs when the waves go into new medium. Refraction waves change speed and reflection waves travel at the same speed.

Waves that strike the surface of a medium at an angle will change direction as they enter the new medium. The waves are ___________.

Refracted

The change in direction of a wave as it crosses the boundary between two media in which wave travels at different speed is?

Refraction

Persistence of a sound as in echo, due to multiple reflections is?

Reverneration

What if the effect on sound when room surfaces are too reflective?

Sound becomes garbled because of multiple reflections of sound called reverberations

What are three examples of the effect of refraction that we can see?

Stars twinkling, pencil appearing bent in water,air above hot stove appears to shimmer

How are reflection and refraction alike?

They occur when waves reach a boundary of a new medium and they involve change in direction of a wave.

The 100% reflection of light strikes the boundary between two medium at an angle greater than the critical angle is?

Total Internal Reflection

Image formed through reflection or refraction that can be seen by an observer but can't be projected on screen b/c light from object does not actually come to focus is what?

Virtual Image

The crest,trough, or any continuous portion of a 2 dimensional or 3 dimensional wave in which the vibrations are all the same way at same time is the __________front.

Wave

What happens to light when it strikes glass or water?

When strike water 2% is reflected and rest transmitted and when strikes glass 4% is reflected rest transmitted.

Does the law of reflection hold for diffuse reflection?

Yes but different reflections in different directions

When a wave reaches a boundary it a. can partially or totally reflect b. cannot reflect into the first medium c. scatters. d. is absorbed into the second medium

a. can partially or totally reflect

The critical angle in total internal reflection occurs when incident light on a surface is a. refracted at 90 degrees to the normal b. reflected at 90 degrees to the normal c. at maximum diffraction d. totally absorbed

a. refracted at 90 degrees to the normal

Refraction occurs when a wave crosses a boundary and changes a. speed and direction b. intensity c. frequency d. amplitude

a. speed and direction

If a wall is very rigid, the wave energy that strikes it will be almost __________________.

all reflected back

What does the law of reflection state?

angle of incidence=angle of reflection are equal

Refracted light that bends away from the normal is light that has a. slowed down b. speeded up c. nearly been absorbed d. diffracted

b. speeded up

When a wave crosses a surface at an angle from one medium into another, why does it "pivot" as it moves across the boundary into the new medium?

because the part of the wave that reaches the new medium first changes speed while the rest doesn't

Why does blue light refract at greater angles than red light in transparent materials?

blue light refracts more because it slows down more than red light

Changes in wind speed and temperature cause sound waves to a. reflect b. reverberate c. refract d. scatter

c. refract

A surface may be a polished reflector or a diffuse reflector depending on the a. color of light b. brightness of light c. wavelength of light d. angle of incoming light

c. wavelength of light

Your image behind a plane mirror is at a distance equal to a. half your height b. half your distance from the mirror c. your distance in front of the mirror d. slightly more than your distance in-front of the mirror

c. your distance in front of the mirror

A rainbow is the result of light in raindrops that undergoes a. internal reflection b. dispersion c. refraction d. all of these

d. all of these

Sound energy can be a. reflected b. absorbed c. transmitted d. all of these

d. all of these

The law of reflection applies to a. only partially reflected waves. b. only totally reflected waves. c. only normal waves. d. both partially and totally reflected waves.

d. both partially and totally reflected waves

Atmospheric refraction occurs with changes in a. wind speed b. air temperature c. the presence of water d. both wind speed and air temperature

d. both wind speed and air temperature

When light incident on a prism separates into a spectrum, we call the process a. reflection b. interference c. diffraction d. dispersion

d. dispersion

What happens to the speed of light as it goes from air to water?

light slows down

What are three conditions that could cause refraction?

light waves change speed when light passes: from one medium to another, through different temperatures of the same medium, and through different densities of the same medium

How much light leaves a medium if it strikes the boundary at an angle greater than the critical angle?

none

Does refraction tend to make objects submerged in water seem shallower or deeper than they really are?

shallow

Light travels in what kind of lines?

straight

Describe the conditions necessary for a motorist to see a mirage.

the air near the surface must be very hot; light speeds up in the hot air and refracts upward

Describe the conditions necessary for a rainbow.

the sun must be shinning in one part of the sky and the water droplets in a cloud or in falling rain must be in the opposite part of the sky

Any angle greater than the critical angle equals what?

total internal reflection

Which way does light bend as it passes from air to water?

toward the normal

Where must you be standing in order to see a rainbow?

with your back to the sun

Does refraction occur for both sound waves and light waves?

yes