What is the role of gravity in free fall motion?

Gravity is the force that causes objects to fall towards the Earth in free fall motion.

In more detail, gravity is a fundamental force that attracts two objects towards each other. In the context of free fall motion, it is the force that pulls objects downwards towards the centre of the Earth. When an object is in free fall, it means that gravity is the only force acting upon it. There are no other forces, such as air resistance, acting on the object.

The acceleration due to gravity on Earth is approximately 9.8 m/s². This means that for every second an object is in free fall, its velocity increases by 9.8 m/s. This is why objects falling from a height pick up speed - they are accelerating due to the force of gravity.

It's important to note that the mass of the object does not affect the rate of free fall. This principle, known as the equivalence principle, was famously demonstrated by Galileo who dropped two balls of different masses from the Leaning Tower of Pisa and found that they hit the ground at the same time. This is because the force of gravity acting on an object is proportional to its mass. So, while a heavier object experiences a greater gravitational force, it also has more mass to accelerate, and these two effects cancel each other out.

In conclusion, gravity plays a crucial role in free fall motion. It is the force that causes objects to fall towards the Earth, and it determines the rate at which they accelerate during their fall. Understanding the role of gravity in free fall motion is fundamental to understanding many aspects of physics, from the motion of falling objects on Earth to the movement of planets in the solar system.