EN: Acceleration due to gravity (g) near Earth is about 9.8 m/s^2. - It is the acceleration of a freely falling object (ignoring air resistance). - g is used in gravitational potential energy: GPE = m g Δh.

中文：近地面重力加速度 g ≈ 9.8 m/s^2。 - 忽略空气阻力时，自由落体的加速度约为 g。 - 在重力势能公式中使用：GPE = m g Δh。