The Optics FilesThe Optics FilesUsing Mirrors and Lenses

Key Objectives:Key Objectives:

The student will investigate and understand the interaction of light waves

Key Objectives:Key Objectives:

Predict the characteristics of the images formed by lenses and mirrors– Illustrate and describe reflection

and refraction of visible light

Key Objectives:Key Objectives:

Describe the behavior of light waves– Understand that light travels in

straight lines and is reflected, absorbed or transmitted

Key Objectives:Key Objectives:

– Understand that light travels through media and undergoes a change in speed that causes it to bend when it does so

Key Objectives:Key Objectives:

– Understand that when light strikes an uneven surface or passes through an opening it can reflect or diffract

Key Objectives:Key Objectives:

– Understand constructive and destructive interference regarding light waves

Law of Reflection

States that the angle of incidence (direction in) is equal to the angle of reflection (direction out)

Reflection

The bouncing back of a ray of light, sound or heat when it hits a surface

Plane Mirror

A mirror with a flat smooth surface it reflects a ‘true’ reversed image– Bathroom Mirror

Concave Mirror

A mirror that is curved inward. (Like a bowl) It reflects an upright larger image when inside the focal point and an inverted smaller image when outside the focal point– Compact or Make-up mirror

Convex Mirror

A mirror that bends outward from the center. It reflects a distorted smaller image but allows you to see around corners.– Bus mirrors– Security mirrors

Diffraction

The change in direction of waves as they bend around a corner/edge or around an obstacle or pass through an opening or slit.

Refraction

The bending of light as light waves pass through different mediums

Concave Lens

A lens that bends inward to center.The light waves move outward as they

pass through causing an image on the other side to appear smaller. – Glasses

Convex Lens

A lens that bends outward from the center.

Convex Lens

As light passes through, it focuses the light into a fine beam and the light and images on the other side appear larger– Magnifying glasses– Reading glasses

Interference

The combination of two or more waves that results in a single wave.

Essential Learnings

Light waves travel in straight lines until they strike an object and then they are either reflected, absorbed or transmitted

Essential Learnings

Reflection is the “bouncing back” of light waves– There is a Law that governs

reflection stating that the Angle of Incidence = Angle of Reflection

Essential Learnings

Refraction is the slowing and bending of light waves as light passes through a medium

Essential Learnings

There are three types of mirrors that reflect light– Plane– Concave– Convex

Essential Learnings

Plane Mirror - Reflects a true sized image, upright and reversed

Essential Learnings

Concave Mirror –Makes a larger upright image inside the focal point, a smaller inverted image outside the focal point

Essential Learnings

Convex –Produce smaller distorted but always upright images

Essential Learnings

There are two types of lenses that refract or bend light– Concave– Convex

Essential Learnings

ConcaveLens – Spreads out (Diverge) light

Convex Lens Focus (Converge) light

Essential Learnings

Diffraction is the bending of light and the production of new waves when waves strike an edge or opening

Essential Learnings

Interference takes place when two or more light or sound waves overlap or combine it can be either:– Constructive – Increases Energy– Destructive – Decreases Energy

Essential Learnings

Constructive Interference – Increases Energy

Destructive – Decreasese Energy