SI Units Flashcards
What are the 7 SI units?
Seconds
Metres
Mols
Amperes
Candela
Kg
Kelvin
What is a second?
Duration of a certain amount of oscillations of a caesium 133 atom
What is a mol?
The amount of substance that has the same amount of particles as there are atoms in 0.012kg (12g) of carbon 12
What is a metre?
Length travelled by light in a vacuum in 1/300 000 000 of a second
What is an ampere?
The current in 2 parallel conductors of infinite length placed 1m apart in a vacuum that would produce a force of 2x10-7 N/m
What is a candela?
The luminous intensity of monochromatic light
What is a Kelvin?
1/273.16 of the thermodynamic triple point of water
What are the SI prefixes for 10-12, 10-9, 10-6, 10-3, 10-2, 10-1, 10 +1 etc?
Pico, nano micro, milli, centi, deci
Deca, hecto, kilo, mega, Giga, tera
What units do we use to note speed?
m.s-1
What units do we use to note velocity?
m.s-1 with direction
What units do we use to note acceleration?
m.s-2
What units do we use to note current density?
A.m2
What unit do we use to measure energy?
Joules J
What unit do we use to measure power?
Watt W
What unit do we use to measure charge?
Coulomb C
What unit do we use to measure capacitance?
Farad F
What unit do we use to measure inductance?
Henry H
What unit do we use to measure magnetic flux?
Weber Wb
What unit do we use to measure magnetic flux density?
Tesla T
How do we change Celsius into Kelvins?
Add 273.15 e.g. 1c = 274.15k
What units do we use to measure newtons?
Kg.m.s-2
What units do we use to measure pascals?
Kg.m-1.s-2
What units do we use to measure joules?
Kg.m2.s-2
What unit do we use to measure Ohms?
Kg.m2.s-3.A-2
How do atmospheres, kPa and bar’s compare to each other at sea level?
1 atmosphere (average pressure at sea level) = 101.3kpa = 1.013 bar
I.e. 1 atm = 100kpa = 1 bar
How does one atm compare to: PSI, mmHg and cmH2O?
1 atm = 14.69 PSI = 760mmHg and 1033 cmH2O
How does 1kpa compare to cmH2O and mmHg?
1kpa = 10.3cmH2O and 7.6mmHg
Ampere gives the quantity of……?
Electrical current
Kg gives the quantity of…..?
Mass
How can you change cmH2O to mmHg?
Multiple by 0.76
What is a googol?
Prefix for 1x10 to the power of 100
What is the prefix Tera in numbers?
1 000 000 000 000
What is the prefix pico in numbers?
0.000 000 000 001
How do we change mmHg to kPa?
Divide by 7.6
