11.4 The Ray Model of Light

Light RayA line and arrow representing the

direction and straight-line path of light

Incident Light Light emitted from a source that strikes an object

Incident Light Ray

Properties of Light When light strikes matter, it can be…

1. Transmitted – light passes through a substance

2. Reflected – light bounces off an object

3. Absorbed – light is absorbed by object and converted to heat

Flat/Plane Mirrors Image:

A reproduction of an original object that is produced through the use of light

Mirror A polished surface reflecting an image

Mirrors

Terminology of Reflection

Terminology of Reflection

NORMAL

Terminology of Reflection

Incident Ray

NORMAL

Terminology of Reflection

Incident Ray

NORMAL

Angle of incident

Terminology of Reflection

Incident Ray

NORMAL

Angle of incident

Reflected Ray

Terminology of Reflection

Incident Ray

NORMAL

Angle of incident

Reflected Ray

Angle of reflection

11.6 Laws of Reflection:Plane (flat) mirrors

Matter can be classified as: Transparent

Transmits all or almost all incident light, object can clearly be seen through material

Ex. Clear glass

Matter can be classified as: Translucent

transmits some incident light but absorbs or reflects the rest, objects are not clearly seen through material

Matter can be classified as: Opaque

Does not transmit any incident light, objects are not seen through material

Try this: Classify each of these materials as transparent,

translucent or opaque: A textbook

Frosted glass

A single sheet of tissue paper

A clean sheet of glass

A rock

Apple juice

Sunglasses

Try this: Classify each of these materials as transparent, translucent

or opaque: A textbook- OPAQUE

Frosted glass- TRANSLUCENT

A single sheet of tissue paper- TRANSLUCENT

A clean sheet of glass- TRANSPARENT

A rock- OPAQUE

Apple juice- TRANSLUCENT

Sunglasses- TRANSPARENT

From our lab, we learned…

angle of incidence = angle of reflection

The incident ray, reflected ray and the normal all lie in the same plane

Light Reflecting off Surfaces

Specular Reflection: Reflection of light off a smooth surface (ex.

mirror)

Light Reflecting off Surfaces

Specular Reflection: Reflection of light off a smooth surface (ex.

mirror)

Light Reflecting off Surfaces

Diffuse Reflection: Reflection of light off a rough surface (ex. moving

water)

Light Reflecting off Surfaces

Diffuse Reflection: Reflection of light off a rough surface (ex. moving

water)

Images in Plant Mirrors

Pg 488- Leonardo da Vinci’s handwriting

Virtual Images An image formed by light coming from an apparent light

source

Light is not arriving at or coming from the actual image location

Characteristics of Images in a Plane Mirror

Lateral Inversion: The orientation of an image in a plane mirror that

is backwards and in reverse order

Reflection Worksheet

Complete the worksheet

Remember that the virtual image must be the same difference from the mirror as the real object

How do we see the image?

Properties of an Image

Use the acronym SALT

Sample Question

Sample Question

Sample Question

S- same size

A- upright

L- 2 cm from mirror

T- virtual