Gravity causes a falling object to accelerate downward on Earth. Earth’s mass creates a gravitational field that attracts objects toward its center, producing the familiar downward pull we call weight.
Near Earth’s surface, the acceleration due to gravity is approximately 9.8 m/s². That means an object’s downward velocity increases by about 9.8 metres per second every second when air resistance is ignored. Newton’s second law explains this through the relationship F = ma, while Newton’s law of universal gravitation explains where the force comes from.
The acceleration is approximately the same for objects of different masses in a vacuum. A feather falls more slowly than a coin in air because air resistance affects the feather more strongly relative to its weight—not because gravity pulls on it less. Galileo’s investigations of falling bodies helped establish this idea centuries before Newton formalized gravitational mechanics.
Earth’s actual gravitational acceleration varies slightly with latitude, altitude, and local geology. Earth’s rotation also reduces apparent gravity a little, especially near the equator.