Definition: Newton's Second Law states that the sum of forces equals mass times acceleration (ΣF = m × d²r/dt²).

Highlight: The direction and magnitude of force directly correlate with the resulting acceleration of an object.

Example: When analyzing mouvement rectiligne uniforme en physique, the net force must be zero for constant velocity motion.

Quote: "ΣF = m × d²r/dt²" represents the fundamental mathematical expression of Newton's Second Law.

Definition: Average velocity (Vitesse moyenne) is calculated as the displacement vector divided by the time interval.

Vocabulary: Instantaneous velocity (vitesse instantanée) represents the immediate velocity at a specific point in time.

Example: The variation in velocity (ΔV) equals zero during uniform rectilinear motion or when an object is at rest.

Highlight: The concept of variation du vecteur vitesse instantané is crucial for understanding motion changes.