Terminology Units
Reference data and engineering information about terminology units for basics applications.
terminologyunits
Overview
Engineering reference data for Terminology Units in basics.
Key Formulas
Ohm's Law
Voltage = Current × Resistance.
Newton's Second Law
Force = mass × acceleration.
Conservation of Energy
Energy balance.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Voltage | V | |
| Current | A | |
| Resistance | Ω | |
| Force | N | |
| Mass | kg | |
| Acceleration | m/s² |
Dimensional Analysis
The following table lists common fluid mechanics terminology, their fundamental dimensions, and their respective units in the Imperial (USCS) and International System of Units (SI).
38 rows
Terminology | Dimensions | Imperial Units (USCS) | SI-units |
|---|---|---|---|
| Acceleration due to gravity | L / T2 | ft/s2 | m/s2 |
| Area | L2 | ft2 | m2 |
| Chezy roughness coefficient | L1/2/ T | ft1/2/s | m1/2/s |
| Critical Depth | L | ft | m |
| Density | F T2/ L4 | lb s2/ ft4 | N s2/m4 |
| Depth | L | ft | m |
| Depth in open channel | L | ft | m |
| Diameter | L | ft | m |
| Distance from solid boundary | L | ft | m |
| Flow rate | L3/ T | ft3/s | m3/s |
| Force | F | lb | N |
| Force due to pressure | F | lb | N |
| Hazen Williams roughness coefficient | L0.37/ T | ft0.37/s | m0.37/s |
| Head loss due to friction | L | ft | m |
| Head of height | L | ft | m |
| Head of weir | L | ft | m |
| Height above datum | L | ft | m |
| Hydraulic radius | L | ft | m |
| Kinematic viscosity | L2/ T | ft2/s | m2/s |
| Length | L | ft | m |
| Manning's roughness coefficient | T / L1/3 | s/ft1/3 | s/m1/3 |
| Mass | F T2/ L | lb s2/ft | N s2/m |
| Modulus of elasticity | F / L2 | lb/in2 (psi) | Pa |
| Perimeter, Weir Height | L | ft | m |
| Pressure | F / L2 | lb/ft2 | Pa |
| Radius | L | ft | m |
| Shear stress | F / L2 | lb/ft2 | Pa |
| Size of roughness | L | ft | m |
| Specific weight | F / L3 | lb/ft3 | kg/m3 |
| Surface tension | F / L | lb/ft | kg/m |
| Time | T | s | s |
| Thickness | L | ft | m |
| Time | T | s | s |
| Total head | L | ft | m |
| Unit flow rate | L3/ T L | ft3/(s ft) | m3/(s ft) |
| Velocity | L / T | ft/s | m/s |
| Viscosity | F T / L2 | lb s/ft | Pa s |
| Weight | F | lbf | N |
Source: engineeringtoolbox.com
Fundamental Dimensions
The dimensions used in the table above are defined by three fundamental quantities:
- L: Length
- F: Force
- T: Time