搜尋結果
1955–1989. Number built. 104. The Lockheed U-2, nicknamed " Dragon Lady ", is an American single- engine, high altitude reconnaissance aircraft operated from the 1950s by the United States Air Force (USAF) and the Central Intelligence Agency (CIA). It provides day and night, high-altitude (70,000 feet, 21,300 meters), all-weather intelligence ...
- 1 August 1955; 68 years ago
- 1955–1989
- 104
In vector calculus, the Jacobian matrix (/ dʒ ə ˈ k oʊ b i ə n /, / dʒ ɪ-, j ɪ-/) of a vector-valued function of several variables is the matrix of all its first-order partial derivatives.When this matrix is square, that is, when the function takes the same number of variables as input as the number of vector components of its output, its determinant is referred to as the Jacobian ...
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At 20 °C (68 °F), the speed of sound in air is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn ), or one km in 2.91 s or one mile in 4.69 s. It depends strongly on temperature as well as the medium through which a ...
Below are two tables which report the average adult human height by country or geographical region. With regard to the first table, original studies and sources should be consulted for details on methodology and the exact populations measured, surveyed, or considered. With regard to the second table, these estimated figures for adult human ...
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is. The parameter is the mean or expectation of the distribution (and also its median and mode ), while the parameter is its standard deviation.
Along with the trumpeter swan, it is one of the longest birds native to North America, with an overall length of about 50 to 70 inches (130 to 180 cm). The beak measures 11.3 to 15.2 inches (290 to 390 mm) in males and 10.3 to 14.2 inches (260 to 360 mm) in females, while its wingspan is around 95 to 120 inches (240 to 300 cm).
See media help. The (International) Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear code words for communicating the letters of the Roman alphabet. Technically a radiotelephonic spelling alphabet, it goes by various names, including NATO spelling alphabet, ICAO phonetic ...