Download Mirrors and Lenses

Mirrors and Lenses
Rays and the Paths of Light Waves
• Mirrors and lenses change the path of light
waves and affect the images that you see.
• Electromagnetic waves (light) travel in a
straight line in all directions away from its
source.
• Because light travels in a straight line you can
use a ray to show its path. Rays are especially
useful to show the path of light after
reflection, refraction, or diffraction.
Mirrors and Reflection of Light
• The shape of a mirror affects
the way light reflects from it.
• Mirrors are classified by their
shape.
– Plane-has a flat surface, image
is right side up and about the
same size, image is reversed
from left to right.
– Concave-curves inward, image
may be right side up or upside
down depending on the
object’s distance from the
mirror, used in car headlights.
– Convex-curves outward, image
is right side up and smaller
than the original object, used
as side mirrors on cars.
Lenses and Refraction of Light
• A lens is a transparent object
that forms an image by
refraction, or the bending of
light.
• Lenses are classified by their
shape.
• No matter what type of lens you
have, the electromagnetic wave
that passes through the center
of the lens is not reflected or
refracted.
• Types of lenses
– Convex-thicker in the middle than
along the edges, used in
magnifying glasses and cameras
– Concave-thinner in the middle
than along the edges, used in
microscopes and eye glasses.
Lasers and Laser Light
• Electromagnetic waves can
be utilized by technological
devices that are used in
every day life.
• A laser is a device that
produces intense visible
light at only one wavelength
and in only one color.
• Laser light is tightly focused
and does not spread out like
non-laser light does.
• Lasers can be used to
precisely cut materials, in
CD players, and in medical
instruments.
Polarized Light
• Polarized light is made
of light waves that
vibrate in only one
plane.
• The light that bounces
off of a horizontal
surface is know as glare.
Glare is an example of
polarized light.