The rate at which objects are pulled down due to gravity is called the acceleration due to gravity, and it's represented by the letter g.

On Earth, the approximate value of g is 9.8 m/s² (meters per second squared). This means that for every second an object falls, its downward velocity increases by 9.8 meters per second.

Important Note: This is an approximation. The actual acceleration due to gravity varies slightly depending on factors like altitude and location on Earth.