Foundations

Static friction is a responsive force with an approximate limit.

Terminal speed depends on the chosen drag model.

Time-integrated net force changes momentum.

Momentum conservation and kinetic-energy conservation are different.

Potential-energy differences encode path-independent work.

Mechanical energy is only part of the total energy.

A linear spring restores displacement toward equilibrium.

Power measures the rate of work or energy transfer.

Rotation stores kinetic energy determined by mass distribution.

No slip constrains velocity at the contact point.

Zero net force alone does not prevent rotation.

Stress and strain need a loading geometry and a constitutive range.

Density is mass per volume; pressure is normal force per area.

A zero gauge reading need not be a vacuum.

A pressure change is transmitted; pressure need not be equal at different heights.

Viscosity relates shear stress to velocity gradient.

Interface forces can support pressure jumps and capillary columns.

Linear restoring acceleration produces sinusoidal motion.

The familiar pendulum period requires a small swing.

A wave’s pattern speed differs from the motion of its medium.

Energy transport grows with squared amplitude and frequency in the linear model.

A decibel value needs a reference and a specified measured quantity.

Slow modulation comes from superposing close frequencies.

Source and observer velocities are measured relative to the medium.

Heat is energy transferred because of a temperature difference.

Thermal size changes depend on temperature and constraints.

Boundary work depends on the process, while internal energy is a state function.

The power law needs an ideal gas and constant heat-capacity ratio.

Restoring the system alone does not establish reversibility.

Use a reversible comparison path to calculate a state-function change.