noun
free fall
Physics term for motion under gravity alone, without other forces such as air resistance.
真空中では、すべての物体が同じ加速度で自由落下する。
In a vacuum, all objects undergo free fall with the same acceleration.
落下 is a general term for falling or dropping, while 自由落下 specifically refers to free fall in physics.
Compound of 自由 (free) and 落下 (fall), directly corresponding to the English term 'free fall'.