It is a vector quantity. The value changes slightly at different locations on the surface of the Earth. The magnitude of is generally different on other celestial bodies. The value of can be determined experimentally. One method of determining g involves measuring the period of a pendulum at low amplitude.
Various factors affect the air resistance on a falling body.
In a medium such as air, falling bodies will eventually reach a terminal velocity . The terminal velocity for objects has different values, depending on various factors such as mass, shape, size, and surface texture. The path that a projectile follows is called its trajectory . It takes the same time to reach the ground as if it were dropped from rest. The shape of the trajectory of a projectile, as with any other type of object experiencing motion, is relative to the frame of reference of an observer.