Unit checker and constants
Most lost marks in these modules are unit slips. Type the units of each term and see what they reduce to.
Result
m^-1 kg s^-2
Same as: Pa (pressure, stress)
Write units with spaces, * or . between them and ^ for powers: m^3, s^-1, or m-3. Prefixes k, M, m, c, u, n work (kPa, mm, kJ). Temperature differences count as K.
Constants and standard values
Common values in these modules. If a question or formula sheet gives a different value, use that one.
| Quantity | Symbol | Value | Units |
|---|---|---|---|
| Gravitational acceleration standard value 9.80665 | g | 9.81 | |
| Universal gas constant = 8314 J kmol^-1 K^-1 | R | 8.314 | |
| Gas constant of air | R_air | 287 | |
| Air cp, cv, gamma (ideal gas, ~300 K) | cp, cv, gamma | 1.005, 0.718, 1.4 | |
| Standard atmospheric pressure | p_atm | 101 325 | |
| Density of water (exam value) 998 at 20 deg C | rho_w | 1000 | |
| Dynamic viscosity of water, 20 deg C | mu | 1.00e-3 | |
| Specific heat of liquid water | c_p | 4.18 | |
| Latent heat of vaporisation, 100 deg C | h_fg | 2257 | |
| Density of air, 20 deg C, 1 atm | rho_air | 1.20 | |
| Dynamic viscosity of air, 20 deg C | mu_air | 1.81e-5 | |
| Density of mercury (exam value) | rho_Hg | 13 600 | |
| Stefan-Boltzmann constant | sigma | 5.670e-8 | |
| Boltzmann constant | k_B | 1.381e-23 | |
| Avogadro constant | N_A | 6.022e23 | |
| 0 deg C | T | 273.15 |