Gravity is the force by which a planet or other massive object attracts anything within its vicinity. On Earth's surface, gravity acts as a downward force, pulling objects towards the center of the planet. This force is responsible for keeping objects, including humans, firmly on the ground.
When an object falls towards the Earth's center, it is essentially being accelerated by the force of gravity. According to Newton's law of universal gravitation, the gravitational force between two objects is directly proportional to their masses and inversely proportional to the square of the distance between their centers.
As an object falls towards the Earth's center, the force of gravity acting upon it remains constant, assuming there are no other significant forces at play (such as air resistance). This means that the object's acceleration due to gravity remains constant as well. Near the surface of the Earth, this acceleration is approximately 9.8 meters per second squared (9.8 m/s²), often rounded to 10 m/s² for simplicity.
Objects falling towards the Earth's center experience an increase in velocity over time due to this constant acceleration. This means that the speed at which the object falls increases as time progresses. If the object falls freely, without any other forces impeding its motion (such as air resistance or friction), it will continue to accelerate until it reaches its maximum possible velocity, called the terminal velocity.
It's worth noting that the Earth's gravitational field is not exactly uniform. It can vary slightly depending on the object's location and altitude, but these variations are generally insignificant for everyday scenarios. Nonetheless, gravity always acts as an attractive force towards the center of the Earth, affecting all objects on its surface.