LIGHT AND COLOUR

Spot the mistake

Spot the mistake

Angle of incidence = angle of reflection

Most things reflect light in all directions, scattering light unevenly. A plane mirror is a flat mirror and reflects light evenly.

Diffuse Reflection

Practical

• Predict which letters of the word ALPHABET looked at from the side in a mirror. Test out your prediction

• When you look at your self in the mirror what is different to how another person sees you.

Practical

• Put a pencil behind the mirror. Place another one in front of the mirror and match the reflection with the pencil behind the mirror. Predict the distance each will be from the mirror. Measure the distance of both pencils from the mirror.

Practical

• Use a ray box on a sheet of white paper of light to shine on to a concave mirror. Draw the rays coming off the mirror.

• Repeat using a convex mirror.

Copy the diagram

THE LAW OF REFLECTION

• The angle of incidence is equal to the angle of reflection.

• The image in a plane mirror is virtual and is the same size as the object.

• Plane mirrors are used in periscopes.

• They are used in rear view mirrors.

• The image is as far behind the mirror is as the object is in front.

• Image is laterally inverted

CONVEX AND CONCAVE MIRRORS

http://micro.magnet.fsu.edu/primer/java/mirrors/concave.html

Convex and Concave Mirrors

•A concave mirror is a converging mirror. Parallel rays of light are reflected through the focal point of a concave mirror.•A convex mirror is a diverging mirror. Parallel rays of light are reflected so that they appear to come from the focal point of a convex mirror.

Molecular Expressions Microscopy Primer: Light and Color - Concave Mirrors: Interactive Java Tutorial

http://micro.magnet.fsu.edu/primer/java/mirrors/convex.html

Uses of Concave Mirrors

• Used to collect light energy, sound, heat, radiation, radar and TV signals.

• If you move close to a concave mirror, then you see a magnified image of yourself. This image is upright and virtual as well as magnified. Shaving and make up mirrors

Uses of Convex Mirrors

• They always produce virtual upright images.

• The image is always smaller than the object.

• They are useful when you want a wide field of view – car driving mirrors or shop security.

THE EYE

• The pupil allows light to enter the eye.• The lens helps to focus the light• Light sensitive cells in the retina detect the

light.• A nerve impulse travels from the retina to

the brain along the optic nerve where it is interpreted.

• The iris helps to change the size of the pupil

Molecular Expressions Microscopy Primer: Light and Color - Human Vision: Interactive Java Tutorial

PERISCOPES