📐 2. Forces & Motion

Newton's First Law: objects remain at rest or move at constant velocity unless acted upon by a force.

Newton's Second Law: F = ma, where F is resultant force, m is mass, a is acceleration.

Newton's Third Law: every action has an equal and opposite reaction.

Weight = mg, where g is gravitational field strength (9.81 N/kg).

Friction opposes motion. The coefficient of friction μ = F/R.

Equilibrium occurs when the resultant force is zero.

Tension is the force transmitted through a string, rope, or cable when pulled.

The moment of a force = force × perpendicular distance from the pivot.