WAVES

WAVE INTERACTIONS

FOUR WAYS WAVES INTERACT

R-R-D-IREFLECTIONREFRACTIONDIFFRACTIONINTERFERENCE

How waves interact with a medium

How waves interact with other waves

LAW OF REFLECTION

Angle of incidence = angle of reflection

Incident rays and reflected rays make equal angles with a line perpendicular to the surface, called the normal.

• The angle between the incident ray and the normal is the angle of incidence.

• The angle between the reflected ray and the normal is the angle of reflection.

• Angle of incidence = Angle of reflection

29.2 The Law of Reflection

Diffuse reflection allows us to see most things around us. a. Light is diffusely reflected from paper in many directions. b. Light incident on a smooth mirror is only reflected in one

direction.

29.4 Diffuse Reflection

Ordinary paper has a rough surface when viewed with a microscope.

As a light wave passes from air into water, its speed decreases.

29.8 Refraction of Light

The extent to which the water waves bend depends on the size of the opening.

31.1 Diffraction and Huygens’ Principle

Concave mirror causes light rays to diverge.

Convex mirror causes light rays to converge.

CONCAVE AND CONVEX MIRRORS

REFLECTION

The bouncing back of a wave when it meets a surface or boundary.

http://www.gmi.edu/~drussell/Demos/reflect/reflect.html

http://www.physicsclassroom.com/mmedia/optics/lr.html

REFRACTION

The bending of a wave as it passes from one medium to another.

http://www.physicsclassroom.com/mmedia/optics/lr.html

Light from pencil moves from air to your eye, through water and glass to your eye, through plastic to your eye

Using diffraction gratings

DIFFRACTION

The bending of a wave as it passes through an opening or by an edge.

Ex.: Hear a voice from around the corner.

http://www.pa.op.dlr.de/acoustics/essay1/beugung_en.html

http://www.infoline.ru/g23/5495/Physics/English/waves.htm

INTERFERENCE

The combination of two or more waves that exist in the same place at the same time.

Constructive Interference (additive effect—in phase)

Destructive Interference (subtractive effect—out of phase)

http://users.erols.com/renau/wave_interference.html

http://www2.biglobe.ne.jp/%7Enorimari/science/JavaEd/e-wave3.html

http://www2.biglobe.ne.jp/%7Enorimari/science/JavaEd/e-wave2.html