Beyond SI Units Flashcards
The amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius, equal to 4.184 J
calorie
Unit of electric current in the cgs system of units, equal to 10 A
abampere or biot
Unit approximately equal to the most probable distance between the nucleus and the electron in a hydrogen atom in its ground state
Bohr length
Unit of magnetic flux density in the cgs system of units, equal to 1 x 10-4 T or 100 μT
gauss
Unit of length defined as the distance at which one astronomical unit subtends an angle of one arcsecond, approximately equal to 3.26 light-years
parsec
Unit of pressure in the cgs system, equal to 0.1 Pa
barye
The time it takes the solar system to revolve once around the galactic core, approximately 250 million years
galactic year
Unit of time equal to 14 days
fortnight
Unit of area equal to (100 m)2, or 10,000 m2
hectare
Unit of spectral flux density, used especially in radio astronomy (named for the founder of radio astronomy who in August 1931 first discovered radio waves emanating from the Milky Way)
jansky
What does FLOPS as a measure of a computer’s computing power stand for?
Floating point Operations Per Second
The mean solar day on the planet Mars
sol
Unit for sedimentation coefficient, defined as exactly 10−13 seconds (named for the winner of the 1926 Nobel Prize in chemistry for his work on disperse systems, colloids and his invention of the ultracentrifuge)
svedberg
A unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres
diopter
What is 1 astronomical unit in kilometers?
150 million km (which equals 150 billion m)
Unit for symbol rate or modulation rate in symbols per second or pulses per second
baud
Unit of length equal to 10-10 m
ångström
Unit of area equal to 10−28 m2 (or 100 fm2), used in nuclear physics for expressing the cross sectional area of nuclei
barn
Unit of length equal to the distance from Earth to the Sun or about 150 million kilometres
astronomical unit
The amount of heat energy needed to raise the temperature of one kilogram of water by one degree Celsius, equal to 4184 J
Calorie (with a capital C) or kilocalorie
What unit of energy is defined to be 4.184 gigajoules?
ton of TNT
Unit of charge in the cgs system
statcoulomb or franklin
Unit of length measuring about 9.46 trillion kilometres
Light-year
What standard unit of mass in astronomy is equal to approximately 2×1030 kg?
solar mass
A unit of information that most commonly consists of eight bits; historically, the number of bits used to encode a single character of text in a computer
byte
Unit of mass equal to 1000 kg
tonne
Unit of volume in the original metric system equal to one cubic metre, invented as a metric analogue to the cord
stère
What is the area of a hectare in square metres?
10 000 m2
The original name for the kilogram
grave
Unit in the cgs system for kinematic viscosity
stokes
Unit equal to 1 rotation of the Earth relative to fixed stars (approximately 23 hours, 56 minutes, 4 SI seconds)
sidereal day
Unit of energy in the cgs system, equal to 10-7 J
erg
The system of natural units based upon the speed of light, the gravitational constant, and the ratio of a photon’s energy to its frequency
Planck units (note that the Planck time is sometimes consider to be the shortest measurable time interval and the Planck length the scale of quantum gravity)
Unit of acceleration in the cgs system of units
galileo
The basic unit of information in information theory and computing, representing a logical value that can have only one of two values
bit
Unit of radioactivity
curie
Unit of pressure equal to 100 000 Pa or 100 kPa
bar
A unit of information normally equal to 4 bits, or one half of the common 8-bit byte
nibble
What unit of energy is equal to 1.602×10−19 joules
electronvolt
Unit of absorbed radiation dose, defined as 0.01 Gy
rad
Unit of measurement for the exposure of X-rays and gamma rays, defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air
röntgen
Unit of force in the cgs system, equal to 10-5 N
dyne
