What is Free fall?
'''Free fall''' is what happens when an object is let to [[Falling|fall]] on its own without [[propulsion]] or [[resistance]]. Someone who is standing is not in free fall, but someone jumping from an aeroplane is, until [[Drag (physics)|air resistance]] builds up, ending in [[terminal velocity]]. An [[artillery]] shell is in free fall from the time it is fired until it hits something. Even the time when it is going up is free fall. [[Space station|Space stations]] and [[spacecraft]] are in free fall when their [[rocket engine|engine]] is not on and they are not sitting somewhere, which means all or most of the time. For [[Earth]] the [[acceleration due to gravity]] (g) is 9.81 [[Newton (unit)]] per kilogram. {{physics-stub}} [[Category:Mechanics]] [[Category:Gravitation]]