Criterio de signos ¿Por qué g es negativo?

Detailed explanation of the sign criterion for falling bodies. Specifically, why the value of g is always negative. Explained with a worked-out example. Many more explanations and examples of movements at:    • Cinemática. Movimientos y velocidades   Horizontal shot solved and explained step by step:    • Tiro horizontal. Explicación y ejemplo res...   On the channel, you also find the theoretical explanation with all the reasoned formulas for oblique or parabolic shots:    • Tiro oblicuo (o parabólico).   And many kinematics exercises:    • Cinemática. Movimientos y velocidades   Boat crossing a river:    • Barco que cruza un río. Composición de mov...