The measurement of 9.81 meters per second is known as the acceleration due to gravity on Earth. This means that, in the absence of air resistance, an object falling freely will increase its speed by approximately 9.81 meters per second for each second it falls. This value is crucial in physics and engineering, as it helps calculate the motion of falling objects. For example, if you drop a ball, it will fall faster and faster, reaching a speed of 9.81 meters per second after one second, 19.62 meters per second after two seconds, and so on.