Physical Quantities
| Quantity | Definition | Formula | Units | Dimensions | |
|---|---|---|---|---|---|
| M E C H A N I C A L |
Length or Distance | fundamental | d | m (meter) | L (Length) |
| Time | fundamental | t | s (second) | T (Time) | |
| Mass | fundamental | m | kg (kilogram) | M (Mass) | |
| Area | distance2 | A = d2 | m2 | L2 | |
| Volume | distance3 | V = d3 | m3 | L3 | |
| Density | mass / volume | d = m/V | kg/m3 | M/L3 | |
| Velocity | distance / time | v = d/t | m/s | L/T | |
| Acceleration | velocity / time | a = v/t | m/s2 | L/T2 | |
| Momentum | mass × velocity | p = mv | kg·m/s | ML/T | |
| Force Weight |
mass × acceleration mass × (accel. of grav.) |
F = ma W = mg |
N (newton) = kg·m/s2 | ML/T2 | |
| Pressure or Stress | force / area | p = F/A | Pa (pascal) = N/m2 = kg/(m·s2) | M/LT2 | |
| Energy or Work Kinetic Energy Potential Energy |
force × distance mass × velocity2 / 2 mass × (accel. of grav.) × height |
E = Fd KE = mv2/2 PE = mgh |
J (joule) = N·m = kg·m2/s2 | ML2/T2 | |
| Power | energy / time | P = E/t | W (watt) = J/s = kg·m2/s3 | ML2/T3 | |
| Impulse | force × time | I = Ft | N·s = kg·m/s | ML/T | |
| Action | energy × time momentum × distance |
A = Et A = pd |
J·s = kg·m2/s | ML2/T | |
| A N G U L A R |
Angle | fundamental | θ | ° (degrees) or rad (radians) 360° = 2π rad |
dimensionless |
| Cycles | fundamental | n | cyc (cycles) | dimensionless | |
| Frequency | cycles / time | f = n/t | Hz (hertz) = cyc/s = 1/s | 1/T | |
| Angular Velocity | angle / time | ω = θ/t | rad/s = 1/s | 1/T | |
| Angular Acceleration | angular velocity / time | α = ω/t | rad/s2 = 1/s2 | 1/T2 | |
| Moment of Inertia | mass × radius2 | I = mr2 | kg·m2 | ML2 | |
| Angular Momentum | radius × momentum (mom. of inert.) × (ang. vel.) |
L = rp L = Iω |
kg·m2/s | ML2/T | |
| Torque | radius × force (mom. of inert.) × (ang. accel.) |
T = rF T = Iα |
N·m = kg·m2/s2 | ML2/T2 | |
| T H E R M A L |
Temperature | fundamental | T | °C (celsius) or K (kelvin) | K (Temp.) |
| Heat | heat energy | Q | J (joule) = kg·m2/s2 | ML2/T2 | |
| Entropy | heat / temperature | S = Q/T | J/K | ML2/T2K | |
| E L E C T R O M A G N E T I C |
Electric Charge (+/-) | fundamental | q | C (coulomb) | C (Charge) |
| Current | charge / time | i = q/t | A (amp) = C/s | C/T | |
| Voltage or Potential | energy / charge | V = E/q | V (volt) = J/C | ML2/CT2 | |
| Resistance | voltage / current | R = V/i | Ω (ohm) = V/A | ML2/C2T | |
| Capacitance | charge / voltage | C = q/V | F (farad) = C/V | C2T2/ML2 | |
| Inductance | voltage / (current / time) | L = V/(i/t) | H (henry) = V·s/A | ML2/T2 | |
| Electric Field | voltage / distance force / charge |
E = V/d E = F/q |
V/m = N/C | ML/CT2 | |
| Electric Flux | electric field × area | φE = EA | V·m = N·m2/C | ML3/CT2 | |
| Magnetic Field | force / (charge × velocity) | B = F/qv | T (tesla) = Wb/m2 = N·s/(C·m) | M/CT | |
| Magnetic Flux | magnetic field × area | φM = BA | Wb (weber) = V·s = J·s/C | ML2/CT |
Mass, energy, momentum, angular momentum, and charge are conserved, which means the the total amount doesn't change in an isolated system.