Search results
Results From The WOW.Com Content Network
The foot per second (plural feet per second) is a unit of both speed (scalar) and velocity (vector quantity, which includes direction). [1] It expresses the distance in feet (ft) traveled or displaced, divided by the time in seconds (s). [2] The corresponding unit in the International System of Units (SI) is the meter per second.
In 1709, the Reverend William Derham, Rector of Upminster, published a more accurate measure of the speed of sound, at 1,072 Parisian feet per second. [5] The Parisian foot was 325 mm . This is longer than the standard "international foot" in common use today, which was officially defined in 1959 as 304.8 mm , making the speed of sound at 20 ...
It is equal to one picocurie of Sr-90 per gram of body calcium. Since about 2% of the human body mass is calcium, and Sr-90 has a half-life of 28.78 years, releasing 6.697+2.282 MeV per disintegration, this works out to about 1.065 × 10 −12 grays per second. The permissible body burden was established at 1,000 S.U.
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. [2] [3] [4] Historically, it was defined as the meridian arc length corresponding to one minute ( 1 / 60 of a degree) of latitude at the equator, so that Earth's polar circumference is very near to 21,600 nautical miles (that is 60 minutes × 360 degrees).
The yard (symbol: yd) [3] [4] is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly 0.9144 meter. A distance of 1,760 yards is equal to 1 mile. The US survey yard is very slightly longer.
One barn is equal to 1.0 × 10 −28 m 2. The name derives from the folk expressions "As big as a barn," and "Couldn't hit the broad side of a barn", used by particle accelerator physicists to refer to the probability of achieving a collision between particles. For nuclear purposes, 1.0 × 10 −28 m 2 is actually rather large. [25]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The lambert (L) is a unit of luminance equal to 10 4 /π cd⋅m −2. The lumerg is a unit of luminous energy equal to 10 −7 lumen-seconds (100 nlm s). The talbot (T) is a unit of luminous energy equal to one lumen-second (1 lm⋅s). The einstein (E) has two conflicting definitions.