Dynamics

Learning objectives

Explain inertia — the way a body's mass resists any change in its motion — and apply F = ma, recognising that the acceleration always points along the resultant force.

State Newton's three laws of motion, and use weight W = mg as the force a gravitational field exerts on a mass.

Define linear momentum p = mv and force as the rate of change of momentum, and use F = Δp/Δt and impulse FΔt = Δp, including the area under a force–time graph.

Describe how friction, drag and air resistance oppose motion, and explain why an object falling through air accelerates at less than g and reaches a terminal velocity.

Apply conservation of momentum to collisions and explosions in one and two dimensions, stating the principle and the condition that no external resultant force acts.

Distinguish elastic from inelastic collisions using kinetic energy, and use equal relative speeds of approach and separation for a perfectly elastic collision.