11.6 Laws of Reflection:Plane (flat) mirrors

Three ways to Classify Matter: 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…The Laws of Reflection

1. angle of incidence = angle of reflection

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

Light Reflecting off Surfaces

Regular (Specular) Reflection: Reflection of light off a smooth shinny surface (ex. mirror)

Light Reflecting off Surfaces

Regular (Specular) Reflection: Reflection of light off a smooth shinny surface (ex. mirror)

Light Reflecting off Surfaces

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

SHOW DEMO

Light Reflecting off Surfaces

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

11.7 Images of Plane Mirrors

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 - the object is not actually behind the mirror

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

Properties of an Image

Use the acronym SALT

How do we see the image?

Draw the Image:

Sample Question

S- same size

A- upright

L- 2 cm from mirror

T- virtual

Sample Question

Reflection Worksheet Complete the worksheet

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

Use equal perpendicular lines to locate the image

Homework:

Work Sheet

Pg 486 # 2-5

Pg 493 # 1-4, 7