Ten calculators covering classical mechanics: how fast something is moving and how quickly that changes, how much force or momentum is involved, how much energy it carries, and how that energy converts from motion to height and back. Force, momentum and the two energy calculators are closely linked — Newton's second law sets force from mass and acceleration, momentum is mass times velocity, and kinetic energy scales with the square of velocity rather than velocity itself, which is why doubling speed quadruples the energy a collision has to absorb rather than merely doubling it.
Calculators in this section
Potential and kinetic energy are opposite sides of the same figure in any system without friction: what a falling object gains in kinetic energy it loses in potential energy, and the two calculators are built to be checked against each other for exactly that reason. Power, separately, measures how quickly energy is transferred or work is done — the same amount of work performed twice as fast means twice the power, independent of how much total energy was involved.
Pressure, density and wavelength sit a little apart from the motion calculators, covering force distributed over area, mass packed into volume, and the spacing of a repeating wave. All ten use the standard formula for the quantity in question, applied exactly as defined, which makes them reliable for checking working or exploring how changing one variable moves the result — not a substitute for understanding why the formula takes the shape it does.