chapter 7 light and geometric optics. 7.2 curved mirrors
TRANSCRIPT
Chapter 7Light and Geometric
Optics
7.2 Curved Mirrors
Types of Curved Mirrors• The images of CURVED MIRRORS are much different than what
you are used to from a “regular,” plane mirrors • Curved mirrors can be used to form images that are larger or
smaller than the object.
Types of Curved Mirrors• The images of CURVED MIRRORS are much different than what
you are used to from a “regular,” plane mirrors • Curved mirrors can be used to form images that are larger or
smaller than the object.
Concave Mirrors Convex Mirrors
Types of Curved MirrorsConcave Mirrors • Used whenever a magnified
image of an object is needed• They can also produce inverted, small images• They produce “real images”• Real image = an image that can be projected onto a screen
Types of Curved Mirrors• The opposite of Concave Mirrors• They curve outwards in the opposite direction of Concave Mirrors• Produce smaller images• A wider angle of view • Always produce virtual images
Convex Mirrors
Concave (Converging) MirrorsImaginary line drawn through the
vertex (V)Perpendicular to the surface of the
mirrorSingle Point through which rays
parallel to PA will reflect
The distance between the Vertex and the Focal Point
Concave (Converging) MirrorsRepresents the centre of the
sphere from which the curved mirror was cut
Represents the distance from the centre of curvature to the mirror
surface
Where Will an Image Form?
•Ray 1 and Ray 2 = follow the Law of Reflection•Ray 3 = any ray travelling through F to the V will be reflected right back•
Where Will an Image Form?Step #1: Draw a ray from the top and bottom of an object parallel to the PA. Its reflection from the mirror must pass through the F
f = R/2
Where Will an Image Form?Step#2: Draw a ray from the top and bottom of an object that passes through the F Its reflection from the mirror must be parallel to the PA. All rays MUST CONVERGE at the Focal Point (F)
Where Will an Image Form?Step#2: Draw a ray from the top and bottom of an object that passes through the F Its reflection from the mirror must be parallel to the PA.All rays MUST CONVERGE at the Focal Point (F)
Characteristics of the Image
TYPE: real
ATTITUDE: inverted
MAGNIFICATION: smaller than the
object
POSITION: Closer to the mirror
Characteristics of the Image
TYPE: real
ATTITUDE: inverted
MAGNIFICATION: smaller than the object
POSITION: Closer to the mirror, between C
and F
real inverted smaller than the objectBetween C and F
real invertedSame size as the objectAt C
real inverted larger than the objectTo the left of C
The Concave Mirror as a Magnifier
TYPE: virtual
ATTITUDE: upright
MAGNIFICATION: larger than the object
POSITION: behind the mirror
When the object is between F and the mirror
The Mirror Equation
Can You Predict The Location Of An Image Formed By A Concave Mirror?
A concave spherical mirror has a focal length of 10.0 cm. Locate the image of a pencil that is placed upright 30.0 cm
from the mirror. Draw a ray diagram to confirm your answer.
Practice Problems 7.2.1 (all)