what is the value of gravitational acceleration on earth
Gravity of Earth The precise strength of Earth's gravity varies depending on location. The nominal "average" value at Earth's surface, known as standard gravity is, by definition, 9.80665 m/s2.[2] This quantity is denoted variously as gn, ge (though this sometimes means the normal equatorial value on Earth, 9.78033 m/s2), g0, gee, or simply g (which is also used for the variable local value). 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 = ma (force = mass × acceleration). Gravitational acceleration contributes to the total acceleration, but other factors, such as the rotation of Earth, also contribute, and, therefore, affect the weight of the object.
Earth's rotation The tangential speed of Earth's rotation at a point on Earth can be approximated by multiplying the speed at the equator by the cosine of the latitude.[40] For example, the Kennedy Space Center is located at latitude 28.59° N, which yields a speed of: cos 28.59° × 1,674.4 km/h (1,040.4 mph; 465.1 m/s) = 1,470.23 km/h (913.56 mph; 408.40 m/s)