Definition
A law of motion stating that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, expressed as Force = Mass × Acceleration (F = ma). For a given mass, a larger applied force produces greater acceleration; for a given force, a larger mass produces less acceleration.
Plain English
Push something harder and it speeds up faster. The heavier it is, the harder you have to push to get the same change in speed.
Context Anchor
Seen in basic aerodynamics when explaining how lift, weight, thrust, and drag affect an airplane's motion.
Derivation
Named after Sir Isaac Newton, the English scientist who published these laws of motion in 1687. 'Second' simply refers to its order in his three laws.
Why Pilots Care
Pilots apply this law to predict how changes in power, control inputs, or aircraft weight will affect acceleration, climb rate, or turn performance.
Analogy
A light shopping cart is easy to speed up or turn with a small push. A heavily loaded cart needs a bigger push to make the same change in motion.
Grounding Statement
On takeoff, the engine's forward push must be greater than the airplane's resistance before the airplane can speed up down the runway.
Intuition Check
Newton's Second Law is not an aviation regulation or operating rule. Here, “law” means a basic physical principle that describes how motion changes when forces act on an object.
Example Sentence 1
Because of Newton's Second Law, the fully loaded aircraft accelerated more slowly down the runway than it did when flown solo earlier that morning.
Example Sentence 2
A heavier airplane requires greater thrust than a lighter one to reach the same acceleration during takeoff.