A 50-pound bowling ball and an 8-pound bowling ball are dropped from a tall building. Which ball will hit first? They will land at the same time How fast something falls due to gravity is determined by a number known as the "acceleration of gravity", which is 9.81 m/s^2 at the surface of our Earth. In one second, any object’s downward velocity will increase by 9.81 m/s because of gravity. This is just the way gravity works - it accelerates everything at exactly the same rate.