UNITS

Measures

Numbers immediately followed by a unit (such as 5s) are treated as measures.
Examples:
1/5s = 1 / (5s) = 0.2 * (1/s)
1/5*s = 1/5 * (1s) = 0.2s
1/5^2rad = 1/5^(2rad)
10kg/5kg = (10kg)/(5kg) = 2
sqrt(4m^2) = 2m

Notation

Prefixes, such as k for kilo or m for milli ... are accepted. There is no space between prefix and unit label!

Integer powers of units are accepted, such as s^2 or mm^-1.(Notation: c^d, where c is a label and d is an integer)

Example: (2.5 kilogram)/(meter*second*second) should be entered as 2.5 kg/ (m*s^2) or shorter 2.5 kg/m s^2

Prefixes

Meaning  Name  Symbol

10^18    exa    E
10^15    peta   P
10^12    tera   T
10^9     giga   G
10^6     mega   M
10^3     kilo   k
10^2     hecto  h
10^1     deka   e
10^-1    deci   d
10^-2    centi  c
10^-3    milli  m
10^-6    micro  u
10^-9    nano   n
10^-12   pico   p
10^-15   femto  f
10^-18   atto   a

Basic Units:

Quantity    Name        Symbol

Money       dollars     Dol
Money       US dollars  USD
Length      meter       m
Mass        kilogram    kg
Time        second      s
Temperture  Kelvin      K
Temperture  degree Celsius    oC   (the conversion between C and K is not
                               yet implemented)
Amount      mole        mol
Current     amps        A
Intensity   decibel     db

Derived Units:

Quantity      Name        Symbol   In Terms of Basic Units

Length         inch        in      0.0254m
Length         foot        ft      0.3048m
Force          Newton      N       kg m/s^2
Force          Pound       lb      4.448 N
Force          Pounds      lbs     4.448 N
Energy         Joule       J       N m
Energy         calories    cal     4.186 J
Power          Watt        W       J/s
Angle          radian      rad     1
Angle          degree      deg     pi/180
Angle          revolution  rev     2 pi
Pressure       Pascal      Pa      N/m^2
Pressure       atmospheres atm     10^5 Pa
Pressure       Torr        Torr    133.32 Pa
Pressure       Torr        torr    133.32 Pa
Time           minute      min     60 s
Time           hour        hr      60 min
Time           day         d       24 hr
Time           year        yr      365 d
Volume         liter       L       10^-3 m^3
EMF            volt        V       kg m^2 /A s^3
Resistance     Ohm         ohm     kg m^2/A^2 s^3
Inductance     Henry       H       kg m^2/A^2 s^2
Capacitance    Farad       F       A^2 s^4/kg m^2
Charge         Coulomb     C       A s
Magnetic flux  Weber       Wb      kg m^2/A s^2
Mag. intensity Tesla       T       kg/A s^2
Frequency      Hertz       Hz      1/s
CyberProf converts all answers to basic units and then compares the numerical answer and the units with the correct solution.

Conversion Factors

Length 
1m = 39.37in = 3.281ft
1in = 2.54cm
1km = 0.621mi 
1 mi = 5280ft = 1.609km
1 light-year = 9.461x1015m
1 angstrom = 10-10m
Mass 
1kg = 103g = 6.85x10-2slug
1slug = 14.59kg
1u = 1.66x10-27kg
Time 
1min = 60s
1h = 60min = 3600s
1day = 24h = 86400s
1year = 365.242days = 3.156x107s
Volume 
1liter = 1000cm3 = 3.531x10-2ft3
1ft3 = 2.832x10^-2M3
1gallon = 3.786liter = 231in3
Angle 
180o = πrad
1rad = 57.30o
1o = 60min = 1.745x10-2rad
Speed 
1km/h = 0.278m/s = 0.621 mi/h
1m/s = 2.237mi/h = 3.281ft/s
1mi/h = 1.61km/h = 0.447m/s = 1.467ft/s
Force 
1N = 0.2248lb = 105dynes
1lb = 4.448N
1dyne = 10-5N = 2.248x10-6lb
Work and Energy 
1J = 107erg = 0.738ft-lb = 0.239cal
1cal = 4.186J
1ft-lb = 1.356J
1Btu = 1.054x103J = 252cal
1J = 6.24x1018eV
1eV = 1.602x10-19J
1kWh = 3.60x106J
Pressure 
1atm = 1.013x105Pa = 14.70lb/in2
1Pa = 1N/m2 = 1.45x10-4lb/in2
1lb/in2 = 6.895x103Pa
Power 
1hp = 550ft-lb/s = 0.746kW
1W = 1J/s = 0.738ft-lb/s
1Btu/h = 0.293W

Available Constants

pi    3.1415927
g     9.8 m/s^2 (not yet implemented)