Search results
Results from the WOW.Com Content Network
1.010 Mm – distance from San Diego to El Paso as the crow flies; 1.100 Mm – length of Italy; 1.200 Mm – length of California; 1.200 Mm – width of Texas; 1.500 Mm – length of the Gobi Desert; 1.600 Mm – length of the Namib, the oldest desert on Earth; 2.000 Mm – distance from Beijing to Hong Kong as the crow flies
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol ′, is a unit of angular measurement equal to 1 / 60 of one degree. [1] Since one degree is 1 / 360 of a turn, or complete rotation, one arcminute is 1 / 21 600 of a turn.
With the invention of the metric system, based on powers of ten, there was an attempt to replace degrees by decimal "degrees" in France and nearby countries, [note 3] where the number in a right angle is equal to 100 gon with 400 gon in a full circle (1° = 10 ⁄ 9 gon).
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 −6 metre).
20 mm / 50 m = 0.4 mrad, or 4 clicks with a 1 / 10 mrad adjustment scope. 50 mm / 1000 m = 0.05 mrad, or 1 click with a 0.05 mrad adjustment scope. In firearm optics, where 0.1 mrad per click is the most common mrad based adjustment value, another common rule of thumb is that an adjustment of 1 / 10 mrad changes ...
One radian is defined as the angle at the center of a circle in a plane that subtends an arc whose length equals the radius of the circle. [6] More generally, the magnitude in radians of a subtended angle is equal to the ratio of the arc length to the radius of the circle; that is, =, where θ is the magnitude in radians of the subtended angle, s is arc length, and r is radius.
In astronomy, the angular size or angle subtended by the image of a distant object is often only a few arcseconds (denoted by the symbol ″), so it is well suited to the small angle approximation. [6] The linear size (D) is related to the angular size (X) and the distance from the observer (d) by the simple formula:
[2] [3] [4] It is equivalent to 1 / 400 of a turn, [5] 9 / 10 of a degree, or π / 200 of a radian. Measuring angles in gradians (gons) is said to employ the centesimal system of angular measurement, initiated as part of metrication and decimalisation efforts. [6] [7] [8] [a]