Gravity

When gravity is the only force acting on an object, the object is said to be in free fall. This can be observed if objects are placed in a vacuum. On Earth, all objects in free fall accelerate at the same rate of 9.8 m/s2, even if the objects have different masses. Typically, objects don’t fall within a vacuum, but instead they fall through the air and experience resistance, which is a type of fluid friction acting in the opposite direction of gravity. Objects with greater surface area will experience more air resistance and accelerate more slowly than objects with less surface area.