Chapter 18 1 Mirrors Plane Mirror a flat
- Slides: 17
Chapter 18 -1 Mirrors
Plane Mirror • a flat, smooth surface • light is reflected by regular reflection rather than by diffuse reflection • Light rays are reflected with equal angles of incidence and reflection.
Plane Mirror • Produces a virtual image which appears to be an equal distance behind the mirror. With a virtual image, the light rays do not actually converge on the point where the image appears. • The object and the image have the same size. • They are pointing in the same direction, so the image is an erect image. • Left and right are reversed which is to say “the front and back of the image are reversed. ”
If you blink your right eye, your mirror image left eye blinks back at you:
Concave Mirrors • A concave mirror reflects light from its inner, (“caved in”) surface. • The principle axis is the straight line perpendicular to the surface of the mirror at its center. The focal point • is the point where all rays parallel to the principal axis meet. • It is half the distance between the mirror and the center of curvature (C). • If you point the principal axis of a concave mirror at the sun, all the rays (which are parallel to each other—at “infinity”) will be reflected through the focus • The distance from the focal point to the mirror along the principal axis is the focal length, f, of the mirror.
Real vs Virtual Images Real Image: • the rays actually converge and pass through the image • it can be seen on a piece of paper Virtual Image: • The rays do not converge at the location of the virtual image • The virtual image cannot be projected on a screen
How to draw Ray Diagrams: • Draw the mirror, principal axis, a vertical line where the principal axis touches the mirror, the image, the focal point (F) and the center of curvature (C). Ray 1 (the parallel ray) is from the object to the mirror parallel to the principal axis. The reflected ray goes through the focal point Ray 2 (the focus ray) is from the object through the focal point. The reflected ray is parallel to the principal axis Where Ray 1 and Ray 2 intersect is the location of the image.
Possible scenarios for Concave Mirrors Object Image
Lens/mirror equation: “If I do I die. ” • f = focal length • do = distance of object from mirror • di = distance of image from mirror
Magnification • the ratio of the size of the image, hi , to the size of the object, ho or
b. How high is the image?
Virtual Images Formed by Concave Mirrors
Image defect in Concave Mirrors Spherical aberration • Parallel Incident Light from outer edge of spherical mirror fails to focus at a point • Fix: Parabolic mirror
Convex Mirrors • A convex mirror is a spherical mirror that reflects light from its outer surface. • Rays reflected from a convex mirror always diverge. • Focal length, f, is a negative number (because F is behind the mirror) • di is negative because the image is behind the mirror • Convex mirrors do not form real images. • Images are reduced in size and so appear far away • “Fisheye lens” the image is small (reduced) but wide ranging (enlarged) field of view; upright image, virtual, reduced (images seem farther away) • Good for security mirrors & rearview mirrors in cars
Problem from Opening Page of Chap 18 in Textbook • Four Butterflies but only one is real. • Identify the images and the shape of lenses that produced them:
End 18 -1
- A mirror with flat surface
- Data plane control plane and management plane
- Flat plate collector with adjustable mirrors
- S.a.l.t mirrors
- Flat smooth mirror
- Clearly explain what is meant by the term geometric optics
- Salt plane mirror
- All images in plane mirrors are apex
- Physics
- Convex mirror is a diverging mirror
- Superimposable mirror image
- Commonwealth fund mirror mirror
- The rearview mirror should be checked
- Paraxial
- Location of plane mirror
- Seeing things in mirrors
- Plane mirror ray diagram
- Plane mirror used in