Foundations

Relate a periodic wave's spatial and temporal repetition.

Current measures charge crossing a chosen surface per unit time.

An electric field assigns force per unit test charge.

Magnetic force depends on charge motion relative to the field.

A linear current-voltage relation requires suitable conditions.

Keep the heat and work sign convention explicit in an energy balance.

Apply entropy increase to the whole isolated system.

A simple gas model relates pressure, amount, volume and temperature.

One photon's energy is proportional to its frequency.

Lorentz transformations preserve a combined space-time separation.

Interaction forces act on different bodies in equal and opposite pairs.

Torque changes angular momentum about a specified origin.

Static fluid pressure rises with depth under gravity.

The hydrostatic upward force equals displaced-fluid weight.

Four field equations connect electric and magnetic fields with charge and current.

A quantum wavefunction evolves according to its Hamiltonian.

A normalized wavefunction assigns probabilities to position intervals.

The elementary charge has an exact SI numerical value.

The Boltzmann constant has an exact SI numerical value.

The mole is linked to a specified number of entities.

A specified frequency fixes the photometric SI reference.

External force controls the mass-weighted centre's acceleration.

A tensor relates rotation to angular momentum.

Body-axis angular acceleration includes rotation of the axes.

Stationary action supplies coordinate equations of motion.

Canonical coordinates and momenta evolve from the Hamiltonian.

Density change balances mass flux through a region.

An ideal steady flow balances pressure, motion and height.

Fluid inertia balances pressure, viscosity and gravity.

Compare inertial and viscous scales of a flow.