Here's why:

* Free Fall: Free fall means the object is only influenced by gravity. There's no air resistance or other external forces affecting its motion.

* Gravity: This is the force of attraction between any two objects with mass. In the case of a falling body, it's the attraction between the object and the Earth.

It's important to note that while air resistance is often present in real-world scenarios, it's ignored in the ideal case of free fall.