From the passage provided, extract the gravitational constant on Earth. Include the units of measurements.

Context: In SI units this acceleration is expressed in metres per second squared or equivalently in newtons per kilogram. Near Earth's surface, the gravity acceleration is approximately 9.81 m/s2, which means that, ignoring the effects of air resistance, the speed of an object falling freely will increase by about 9.81 metres per second every second. This quantity is sometimes referred to informally as little g.

The precise strength of Earth's gravity varies depending on the location. The nominal "average" value at Earth's surface, known as standard gravity is, by definition, 9.80665 m/s2. This quantity is denoted variously as gn, ge, g0, gee, or simply g.

The weight of an object on Earth's surface is the downwards force on that object, given by Newton's second law of motion, or F = m a. Gravitational acceleration contributes to the total gravity acceleration, but other factors, such as the rotation of Earth, also contribute, and, therefore, affect the weight of the object. Gravity does not normally include the gravitational pull of the Moon and Sun, which are accounted for in terms of tidal effects.

Answer: 9.80665 m/s2 or 32.1740 ft/s2