Cambridge IGCSE·Co-ordinated Sciences 0654·Physics
Forces
Key knowledge — Forces
Formulas & equations
Weight = mass × gravitational field strength (W = mg)Newton's 2nd law: F = maMoment = force × perpendicular distance from pivotPressure = force ÷ area (P = F/A)Hooke's law: F = kx (extension proportional to force, up to elastic limit)Momentum = mass × velocity (p = mv)Impulse = force × time = change in momentum (Ft = Δmv)
Key facts & rules
- Newton's 1st law: object stays at rest or constant velocity unless acted on by a net force.
- Newton's 3rd law: every action has an equal and opposite reaction (different objects, same type of force).
- Terminal velocity: when drag force = weight → net force = 0 → constant velocity.
- Principle of moments: for equilibrium, sum of clockwise moments = sum of anticlockwise moments.
- Centre of gravity: point where weight acts. Lower CG = more stable.
- Friction: force opposing relative motion between surfaces.
IGCSE Physics — Forces
2449 Cambridge IGCSE 0654 physics past paper questions on forces, organised by subtopic. Pick a subtopic to start practising.
About forces on IGCSE 0654
Forces and their effects, mass and weight, Hooke's law, moments, and Newton's laws of motion.