File Name: concave and convex mirrors .zip
We have already looked at reflection by plane mirrors in topic 8. When the reflecting surface is instead curved, we call it a curved mirror.
We only have to look as far as the nearest bathroom to find an example of an image formed by a mirror. Images in flat mirrors are the same size as the object and are located behind the mirror. Like lenses, mirrors can form a variety of images. For example, dental mirrors may produce a magnified image, just as makeup mirrors do. Security mirrors in shops, on the other hand, form images that are smaller than the object.
Predating even crude lenses, mirrors are perhaps the oldest optical element utilized by man to harness the power of light. Prehistoric cave dwellers were no doubt mesmerized by their reflections in undisturbed ponds and other bodies of water, but the earliest man-made mirrors were not discovered until Egyptian pyramidal artifacts dating back to around BC were examined. Mirrors made during the Greco-Roman period and the Middle Ages consisted of highly polished metals, such as bronze, tin, or silver, fashioned into slightly convex disks, which served mankind for over a millennium. It was not until the late Twelfth or early Thirteenth Centuries that the use of glass with a metallic backing was developed to produce looking glasses , but refinement of this technique took an additional several hundred years. By the Sixteenth Century, Venetian craftsmen were fabricating handsome mirrors fashioned from a sheet of flat glass coated with a thin layer of mercury-tin amalgam see Figure 1 for a Gothic version. Over the next few hundred years, German and French specialists developed mirror-making into a fine art, and exquisitely crafted mirrors decorated the halls, dining, living, and bedrooms of the European aristocracy. Finally, in the mids, German organic chemist Justus von Liebig devised a method for depositing metallic silver onto a pre-etched glass surface by chemically reducing an aqueous solution of silver nitrate.
A curved mirror is a mirror with a curved reflecting surface. The surface may be either convex bulging outward or concave recessed inward. Most curved mirrors have surfaces that are shaped like part of a sphere , but other shapes are sometimes used in optical devices. The most common non-spherical type are parabolic reflectors , found in optical devices such as reflecting telescopes that need to image distant objects, since spherical mirror systems, like spherical lenses , suffer from spherical aberration. Distorting mirrors are used for entertainment.
the mirror on the inner, or concave, side of the curve. •A convex spherical mirror has the silvered surface of the mirror on Image Formed by a Concave Mirror.
The properties of spherical mirrors are discussed as we learn such terms as center of curvature, focal point, and principal axis. The properties of images formed by concave and convex mirrors are examined through ray diagrams. Plan and carry out investigations to characterize the properties and behavior of electromagnetic waves. Plan and carry out investigations to describe common features of light in terms of color, polarization, spectral composition, and wave speed in transparent media.
The image in a plane mirror has the same size as the object, is upright, and is the same distance behind the mirror as the object is in front of the mirror. A curved mirror, on the other hand, can form images that may be larger or smaller than the object and may form either in front of the mirror or behind it. In general, any curved surface will form an image, although some images make be so distorted as to be unrecognizable think of fun house mirrors.
A concave mirror has the reflecting surface that caves inwards. Concave mirrors converge light to one prime focus point. Therefore, they are also called converging mirrors.
Lateral visibility at road junctions can be improved by a convex mirror. Mainly in built-up areas, where visibility on one or both sides of an intersection may be hampered by space limitations, such a device is attractive because of its low cost and its actuated operating mode. However, little information is yet available concerning its efficiency and optimisation. The usefulness of a convex mirror from a safety viewpoint is experimentally assessed in a road junction where drivers who have to give way can observe lateral traffic through a convex mirror. Comparison is made between mirror users and non-users, in relation to their give way behaviour. The main finding is that the mirror appears as a device that enhances safety behaviour and can be recommended as a traffic aid. Abstract Lateral visibility at road junctions can be improved by a convex mirror.
Обычно же открытый текст поступал на принтер Стратмора за считанные минуты.
In the first section of Lesson 4 , we learned that light is reflected by convex mirrors in a manner that a virtual image is formed.Reply
Optical lenses are polished glass or plastic substrates that are shaped with one or more curved surfaces that transmit light.Reply
There are, again, two alternative methods of locating the image formed by a convex mirror.Reply