The equation is stated as follows: The magnification equation relates the ratio of the image distance and object distance to the ratio of … Derivation. In a spherical mirror: The distance between the object and the pole of the mirror is called the object distance (u). It’s used to calculate the radius of curvature and focal length of a curved mirror. Figurative use, "that in or by which anything is shown or exemplified," hence "a model (of good or virtuous conduct)" is attested from c. 1300. What is a focal length? The equation is stated as follows: The magnification equation relates the ratio of the image distance and object distance to the ratio of … mirror (n.) mid-13c., mirour, "polished surface (of metal, coated glass, etc.) Mirror ball attested from 1968. used to reflect images of objects," especially the face of a person, from Old French mireoir "a reflecting glass, looking glass; observation, model, example," earlier miradoir (11c. The Spanish cognate, mirador (from mirar "to look, look at, behold"), has come to mean "watch tower, gallery commanding an extensive view." An ancient Germanic group of words for "mirror" is represented by Gothic skuggwa, Old Norse skuggsja, Old High German scucar, which are related to Old English scua "shade, shadow.". The mirror equation is, 1/O + 1/I = 2/R = 1/f. mid-13c., mirour, "polished surface (of metal, coated glass, etc.) The mirror equation expresses the quantitative relationship between the object distance (d o), the image distance (d i), and the focal length (f). The derivation of the mirror formula is one of the most common questions asked in various board examinations as well as competitive examinations. Latin speculum "mirror" (or its Medieval Latin variant speglum) is the source of words for "mirror" in neighboring languages: Italian specchio, Spanish espejo, Old High German spiegal, German Spiegel, Dutch spiegel, Danish spejl, Swedish spegel. The mirror equation expresses the quantitative relationship between the object distance (d o), the image distance (d i), and the focal length (f). The image A 1 B 1 is formed at a distance 'v' from the mirror. Mirror image "something identical to another but having right and left reversed" is by 1864. It is an equation relating object distance and image distance with focal length is known as a mirror equation. Related: Mirrored; mirroring. ", polished surface that forms images by reflecting light. A mirror formula can be defined as the formula which gives the relationship between the distance of object ‘u’, … Mirror Formula (Concave Mirror) Mirror formula is the relationship between object distance (u), image distance (v) and focal length. The Middle English verb mirouren (early 15c.) The figure shows an object AB at a distance 'u' from the pole of a concave mirror. Belief that breaking one brings bad luck is attested from 1777. The position of the image is obtained by drawing a ray diagram. "to reflect," 1590s, from mirror (n.). meant "to be a model" (for conduct, behavior, etc. To look in (the) mirror in the figurative sense of "examine oneself" is by early 15c. https://www.khanacademy.org/.../mirrors/v/derivation-of-the-mirror-equation ), from mirer "look at" (oneself in a mirror), "observe, watch, contemplate," from Vulgar Latin *mirare "to look at," variant of Latin mirari "to wonder at, admire" (see miracle). used to reflect images of objects," especially the face of a person, from Old French mireoir "a reflecting glass, looking glass; observation, model, example," earlier miradoir (11c. The focal length is the distance from the center of the mirror in which reflect light is most densely focused. ), while miren (mid-14c., from Old French mirer) meant "to look in a mirror. It is also known as a mirror formula. 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