EPS: Light

Light

Behavior of Light

●When light hits an object, light can be Refracted, Reflected, Absorbed

Fill in the Blanks

When light hits an object, the light is _____, or _____ or _____

Refraction

Refraction: The bending of a light wave caused by a change in its speed as it
moves from one medium to another

Index of Refraction: indicates how much of a material reduces the speed of light;
the more light slowed the greater the index of refraction

Refraction in Different Mediums

●Some mediums cause light to bend more than others

●When light passes from air to water light slows down as indicated by a less
steep line

QUESTION: On the image below, draw the changes in the
path of light as light goes from one medium to another.
(Draw the path of light as a straight line)

AIR

WATER

Match

Match the following

• Refraction

• Index of refraction

• Medium

Bending of a light wave caused by a chance in its speed due to movement from a medium

How much of a material reduces the speed of light

the substance that transfers the energy, or light

• Bending of a light wave caused by a chance in its speed due to movement from a medium

• How much of a material reduces the speed of light

• the substance that transfers the energy, or light

Prisms and Rainbows

●When white light enters a prism, each wavelength is refracted by a different
amount

●The longer the wavelength, the less the wave is bent by a prism

The more the wave is bent.

shorter wavelength

Less the wave is bent

LONGER Wavelength

Prism- Refraction - Wavelength

Question! Which color of light in the visible spectrum is
refracted the most and the least?

Color refracted the most:
Color refracted the least:

Mirages

●Mirage: An image of a distant object caused by refraction of light

Multiple Choice

Why does the straw appear to be bent?w

• light is reflected

• light is absorbed

• light is turned

• light is refracted

Multiple Choice

What do we call a material that light can travel through?

• air

• water

• medium

• pathway

Multiple Choice

When light bends it is ______

• Reflection

• Absorption

• refraction 

• optical density

Multiple Choice

Which color of light is bent most during refraction by a prism?

• red

• yellow

• green

• violet

Multiple Choice

Which color of light is bent the least during refraction by a prism?

• red

• yellow

• green

• violet

Multiple Choice

The longer a wavelength, the ______ the wave is bent by a prism

• less

• more

Multiple Choice

T or F. The type of medium can affect how much light is refracted

• T

• F

Reflection

Reflection: When a light wave bounces off an object and changes directions

Law of Reflection: The angle of incidence (i), or where light strikes a surface, is
equal to the angle of reflection (r)

Types of Reflection

Regular Reflection: rays hit a smooth surface, angle (i) = angle (r) , creates a
clear image

Diffuse Reflection: rays hit an uneven surface, angle (i) does NOT = angle (r) ,
not a clear image

Absorption or Transmitted Through

● Light waves could be absorbed by an object, if absorbed,

no color will be seen (for example- black pigment)

● The more transparent an object is the less light it will

absorb

● Light waves can be transmitted through an object, if light

energy moves through an object (for example- glass)

Match

Match the following

• Regular reflection

• Diffuse reflection

Regular reflection image

Diffuse Reflection image

clear image

not a clear image

• Regular reflection image

• Diffuse Reflection image

• clear image

• not a clear image

Fill in the Blanks

The angle of incidence (i), or where light strikes a surface, is equal to the angle of reflection (r)

Types of Materials that Interact with Light

1.

Opaque

○No light passes through these materials

○Most of the light is either reflected or absorbed

○Most materials (ex. desk , pan, wall)

Types of Materials that Interact with Light

2. Translucent

●Only some light passes through these materials

●Light changes directions many times and is scattered as it passes through

●Ex. Clouds, frosty glass

Types of Materials that Interact with Light

3. Transparent

●Almost all light passes directly through these materials

●Can be absorbed or reflected a little

●You can see clearly through them

●Ex. Eye-glasses

Reorder

Reorder the following from most light absorbed to least

• Opaque

• Translucent

• Transparent

1

2

3

• 1
• 2
• 3