Since the radius of Earth is far greater(rough: 6400km) than a few 100m, you can neglect that distance and still have g=9.80 (g=GM/(R^2), with R being the radius of earth, a few 100m dont do much difference in g's equation)
In general, when near the Earth's surface, scientists use 9.8 meters per seond^2 since the slight difference in elevation along the Earth's surface doesn't affect the acceleration very much. But if you want the exact formula it is: (G(msub1)(msub2))/radius^2. msub1 and msub2 are the masses of the two objects, and G is 6.67x10^(-11), the gravitational constant.
silicon & oxygen.
i believe roughly 70% (not completely sure though) I'm not really sure, but something like 70% of the earths surface..
Uplift
The earths surface, a building, and a moving object
When objects free fall near Earth's surface, they experience constant acceleration due to gravity. This means that the objects increase their velocity by the same amount each second while falling. The acceleration due to gravity near Earth's surface is approximately 9.8 m/s^2.
Constant acceleration
Force (newtons) = mass (kg) * acceleration (m/s/s) > Acceleration at earths surface radius = 9.82 m/s/s
Free fall acceleration can be considered constant near Earth's surface because the gravitational force acting on an object is primarily determined by the mass of the Earth and the distance from its center. Within a few hundred miles of Earth's surface, these factors do not vary significantly, resulting in a consistent acceleration due to gravity of approximately 9.81 m/s^2. Therefore, objects in free fall experience a nearly constant acceleration regardless of their mass or size.
the water cycle
The acceleration of an object in free fall at Earth's surface is approximately 9.8 m/s^2, which is due to the force of gravity. This acceleration is constant regardless of the mass of the object, as long as air resistance is negligible.
That it is exactly 32f/sec^2 not sure. That it is constant depends on the Earths' mass which is fairly constant.
on the surfaceNote:Since the earth's composition is not homogeneous, the gravitational acceleration onthe surface is probably less than what it is some small distance below the surface,but it's certainly greater than at the center.
Strictly speaking its not the same . This equation calculates the acceleration: acceleration = ( G * ( m1 + m2 ) ) / d2 where: G = newtons gravity constant m1 = earths mass (kg) m2 = objects mass (kg) d = distance between centres of gravity (metres) The earths mass is so large however, only a significantly large object mass would make a real difference to the acceleration.
The acceleration due to gravity decreases with height above the Earth's surface according to the inverse square law. Therefore, at a height of approximately 3186 km above the Earth's surface, the acceleration due to gravity would be half of what it is on the surface. This is known as the point of geosynchronous orbit.
earth is 81.3 times the mass of the moon . acceleration due to gravity at earths surface = 9.82 (m/s)/s acceleration due to gravity at moons surface = 1.62 (m/s)/s . 1 kg at earths surface, force = 1 * 9.82 = 9.82 newtons 1 kg at moons surface, force = 1 * 1.62 = 1.62 newtons
because all are measured at the same radius from the earths cog, if you doubled this distance, the acceleration would be only one quarter that of the surface