Gravity is the rate at which an object in free fall accelerates by every second, written the same as any other acceleration, that is to say speed/seconds^2. The force of gravity as measured by the amount of newtons that pull down on a one kilogram block when suspended from a scale is 9.8. As a newton is the amount of force necessary to move one kilogram one meter at rate of one meter per second, the acceleration from gravity is 9.8 meters a second a second.