Mechanics

Sum of two vectors is the diagonal of the parallelogram they form.

Any vector splits into perpendicular components along chosen axes.

Three equations relate u, v, a, s, t under constant acceleration.

Uniform horizontal + free fall vertical = parabolic trajectory.

Without an external force, motion doesn't change — at rest stays at rest, moving keeps moving.

Acceleration is proportional to force, inversely to mass.

Every action has an equal and opposite reaction — on two different bodies.

Friction before motion is larger than during motion — two different coefficients.

Constant-speed circular motion still has centripetal acceleration.

Force between two masses ∝ product of masses, inverse square of distance.

Net work equals change in kinetic energy.

Without dissipative forces, KE + PE stays constant.

Total momentum of an isolated system stays constant.

Force × time = change in momentum.